EP3759247A1 - Verfahren zur primer-verlängerungsreaktion mit verbesserter spezifität - Google Patents
Verfahren zur primer-verlängerungsreaktion mit verbesserter spezifitätInfo
- Publication number
- EP3759247A1 EP3759247A1 EP19711506.6A EP19711506A EP3759247A1 EP 3759247 A1 EP3759247 A1 EP 3759247A1 EP 19711506 A EP19711506 A EP 19711506A EP 3759247 A1 EP3759247 A1 EP 3759247A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- primer
- sequence
- oligonucleotide
- template
- primer extension
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000000034 method Methods 0.000 title claims abstract description 194
- 238000006243 chemical reaction Methods 0.000 title claims description 527
- 230000001976 improved effect Effects 0.000 title abstract description 11
- 108091034117 Oligonucleotide Proteins 0.000 claims abstract description 1276
- 239000002773 nucleotide Substances 0.000 claims abstract description 402
- 125000003729 nucleotide group Chemical group 0.000 claims abstract description 398
- 230000015572 biosynthetic process Effects 0.000 claims description 378
- 150000007523 nucleic acids Chemical group 0.000 claims description 367
- 230000000295 complement effect Effects 0.000 claims description 347
- 238000003786 synthesis reaction Methods 0.000 claims description 336
- 230000027455 binding Effects 0.000 claims description 326
- 230000003321 amplification Effects 0.000 claims description 265
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 265
- 102000039446 nucleic acids Human genes 0.000 claims description 153
- 108020004707 nucleic acids Proteins 0.000 claims description 153
- 230000001419 dependent effect Effects 0.000 claims description 95
- 238000002844 melting Methods 0.000 claims description 39
- 230000008018 melting Effects 0.000 claims description 39
- 230000000694 effects Effects 0.000 claims description 31
- 108091028043 Nucleic acid sequence Proteins 0.000 claims description 16
- 239000011159 matrix material Substances 0.000 claims description 15
- 108010014303 DNA-directed DNA polymerase Proteins 0.000 claims description 14
- 102000016928 DNA-directed DNA polymerase Human genes 0.000 claims description 14
- 239000000758 substrate Substances 0.000 claims description 14
- 239000013256 coordination polymer Substances 0.000 claims description 13
- 238000012217 deletion Methods 0.000 claims description 12
- 230000037430 deletion Effects 0.000 claims description 12
- 108090000623 proteins and genes Proteins 0.000 claims description 12
- 238000003780 insertion Methods 0.000 claims description 10
- 230000037431 insertion Effects 0.000 claims description 10
- 239000001226 triphosphate Substances 0.000 claims description 10
- 235000011178 triphosphate Nutrition 0.000 claims description 10
- -1 ribonucleoside triphosphates Chemical class 0.000 claims description 8
- 239000002777 nucleoside Substances 0.000 claims description 7
- 230000009870 specific binding Effects 0.000 claims description 7
- 238000006467 substitution reaction Methods 0.000 claims description 6
- 125000002264 triphosphate group Chemical class [H]OP(=O)(O[H])OP(=O)(O[H])OP(=O)(O[H])O* 0.000 claims description 5
- 239000005549 deoxyribonucleoside Substances 0.000 claims description 4
- 150000003833 nucleoside derivatives Chemical class 0.000 claims description 4
- 229920000642 polymer Polymers 0.000 claims description 4
- 239000002342 ribonucleoside Substances 0.000 claims description 4
- 108020004635 Complementary DNA Proteins 0.000 claims description 3
- 230000004044 response Effects 0.000 claims description 3
- 241000282414 Homo sapiens Species 0.000 claims description 2
- 125000003835 nucleoside group Chemical group 0.000 claims description 2
- 230000002194 synthesizing effect Effects 0.000 claims description 2
- 241000124008 Mammalia Species 0.000 claims 1
- 244000052616 bacterial pathogen Species 0.000 claims 1
- 239000000047 product Substances 0.000 description 605
- 238000012986 modification Methods 0.000 description 230
- 230000004048 modification Effects 0.000 description 229
- JLCPHMBAVCMARE-UHFFFAOYSA-N [3-[[3-[[3-[[3-[[3-[[3-[[3-[[3-[[3-[[3-[[3-[[5-(2-amino-6-oxo-1H-purin-9-yl)-3-[[3-[[3-[[3-[[3-[[3-[[5-(2-amino-6-oxo-1H-purin-9-yl)-3-[[5-(2-amino-6-oxo-1H-purin-9-yl)-3-hydroxyoxolan-2-yl]methoxy-hydroxyphosphoryl]oxyoxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(6-aminopurin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(6-aminopurin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(6-aminopurin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(6-aminopurin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxyoxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(4-amino-2-oxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(5-methyl-2,4-dioxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(6-aminopurin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(6-aminopurin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(4-amino-2-oxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(4-amino-2-oxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(4-amino-2-oxopyrimidin-1-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(6-aminopurin-9-yl)oxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-5-(4-amino-2-oxopyrimidin-1-yl)oxolan-2-yl]methyl [5-(6-aminopurin-9-yl)-2-(hydroxymethyl)oxolan-3-yl] hydrogen phosphate Polymers Cc1cn(C2CC(OP(O)(=O)OCC3OC(CC3OP(O)(=O)OCC3OC(CC3O)n3cnc4c3nc(N)[nH]c4=O)n3cnc4c3nc(N)[nH]c4=O)C(COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3COP(O)(=O)OC3CC(OC3CO)n3cnc4c(N)ncnc34)n3ccc(N)nc3=O)n3cnc4c(N)ncnc34)n3ccc(N)nc3=O)n3ccc(N)nc3=O)n3ccc(N)nc3=O)n3cnc4c(N)ncnc34)n3cnc4c(N)ncnc34)n3cc(C)c(=O)[nH]c3=O)n3cc(C)c(=O)[nH]c3=O)n3ccc(N)nc3=O)n3cc(C)c(=O)[nH]c3=O)n3cnc4c3nc(N)[nH]c4=O)n3cnc4c(N)ncnc34)n3cnc4c(N)ncnc34)n3cnc4c(N)ncnc34)n3cnc4c(N)ncnc34)O2)c(=O)[nH]c1=O JLCPHMBAVCMARE-UHFFFAOYSA-N 0.000 description 127
- 238000006073 displacement reaction Methods 0.000 description 117
- 239000012071 phase Substances 0.000 description 115
- 108700028369 Alleles Proteins 0.000 description 113
- 108020004414 DNA Proteins 0.000 description 70
- 230000003993 interaction Effects 0.000 description 70
- 238000000926 separation method Methods 0.000 description 55
- 230000000903 blocking effect Effects 0.000 description 54
- 239000002585 base Substances 0.000 description 53
- 239000000203 mixture Substances 0.000 description 46
- 108091033319 polynucleotide Proteins 0.000 description 46
- 239000002157 polynucleotide Substances 0.000 description 46
- 102000040430 polynucleotide Human genes 0.000 description 46
- 239000012634 fragment Substances 0.000 description 43
- 230000008569 process Effects 0.000 description 41
- 239000011541 reaction mixture Substances 0.000 description 38
- 238000010494 dissociation reaction Methods 0.000 description 36
- 230000005593 dissociations Effects 0.000 description 36
- 230000006870 function Effects 0.000 description 36
- 230000000977 initiatory effect Effects 0.000 description 32
- 238000013459 approach Methods 0.000 description 30
- IQFYYKKMVGJFEH-XLPZGREQSA-N Thymidine Chemical group O=C1NC(=O)C(C)=CN1[C@@H]1O[C@H](CO)[C@@H](O)C1 IQFYYKKMVGJFEH-XLPZGREQSA-N 0.000 description 27
- 229910052799 carbon Inorganic materials 0.000 description 26
- 238000001514 detection method Methods 0.000 description 26
- 239000000523 sample Substances 0.000 description 26
- 239000000975 dye Substances 0.000 description 24
- 239000000178 monomer Substances 0.000 description 23
- 108091032973 (ribonucleotides)n+m Proteins 0.000 description 21
- 239000000243 solution Substances 0.000 description 20
- 239000000872 buffer Substances 0.000 description 17
- 230000035772 mutation Effects 0.000 description 17
- 230000001404 mediated effect Effects 0.000 description 15
- 238000012876 topography Methods 0.000 description 15
- WRADPCFZZWXOTI-BMRADRMJSA-N (9E)-10-nitrooctadecenoic acid Chemical compound CCCCCCCC\C([N+]([O-])=O)=C/CCCCCCCC(O)=O WRADPCFZZWXOTI-BMRADRMJSA-N 0.000 description 14
- 238000003556 assay Methods 0.000 description 13
- 230000002255 enzymatic effect Effects 0.000 description 13
- 230000036961 partial effect Effects 0.000 description 13
- 101150036912 Segment-5 gene Proteins 0.000 description 12
- 125000004429 atom Chemical group 0.000 description 12
- 230000008859 change Effects 0.000 description 12
- 230000002441 reversible effect Effects 0.000 description 12
- 238000007086 side reaction Methods 0.000 description 12
- 108010006785 Taq Polymerase Proteins 0.000 description 11
- 238000009830 intercalation Methods 0.000 description 11
- 239000007790 solid phase Substances 0.000 description 11
- 230000002269 spontaneous effect Effects 0.000 description 11
- YBJHBAHKTGYVGT-ZKWXMUAHSA-N (+)-Biotin Chemical compound N1C(=O)N[C@@H]2[C@H](CCCCC(=O)O)SC[C@@H]21 YBJHBAHKTGYVGT-ZKWXMUAHSA-N 0.000 description 10
- 238000002360 preparation method Methods 0.000 description 10
- 239000000126 substance Substances 0.000 description 10
- RYYWUUFWQRZTIU-UHFFFAOYSA-K thiophosphate Chemical compound [O-]P([O-])([O-])=S RYYWUUFWQRZTIU-UHFFFAOYSA-K 0.000 description 10
- WKKCYLSCLQVWFD-UHFFFAOYSA-N 1,2-dihydropyrimidin-4-amine Chemical compound N=C1NCNC=C1 WKKCYLSCLQVWFD-UHFFFAOYSA-N 0.000 description 9
- YKBGVTZYEHREMT-KVQBGUIXSA-N 2'-deoxyguanosine Chemical compound C1=NC=2C(=O)NC(N)=NC=2N1[C@H]1C[C@H](O)[C@@H](CO)O1 YKBGVTZYEHREMT-KVQBGUIXSA-N 0.000 description 9
- OLXZPDWKRNYJJZ-UHFFFAOYSA-N 5-(6-aminopurin-9-yl)-2-(hydroxymethyl)oxolan-3-ol Chemical compound C1=NC=2C(N)=NC=NC=2N1C1CC(O)C(CO)O1 OLXZPDWKRNYJJZ-UHFFFAOYSA-N 0.000 description 9
- DWRXFEITVBNRMK-UHFFFAOYSA-N Beta-D-1-Arabinofuranosylthymine Natural products O=C1NC(=O)C(C)=CN1C1C(O)C(O)C(CO)O1 DWRXFEITVBNRMK-UHFFFAOYSA-N 0.000 description 9
- 101710163270 Nuclease Proteins 0.000 description 9
- IQFYYKKMVGJFEH-UHFFFAOYSA-N beta-L-thymidine Natural products O=C1NC(=O)C(C)=CN1C1OC(CO)C(O)C1 IQFYYKKMVGJFEH-UHFFFAOYSA-N 0.000 description 9
- 239000003795 chemical substances by application Substances 0.000 description 9
- 238000013461 design Methods 0.000 description 9
- 230000002068 genetic effect Effects 0.000 description 9
- 229940029575 guanosine Drugs 0.000 description 9
- 230000001965 increasing effect Effects 0.000 description 9
- 230000035484 reaction time Effects 0.000 description 9
- 229940104230 thymidine Drugs 0.000 description 9
- 101000932768 Conus catus Alpha-conotoxin CIC Proteins 0.000 description 8
- 101000922002 Conus purpurascens Conotoxin p5a Proteins 0.000 description 8
- OIRDTQYFTABQOQ-KQYNXXCUSA-N adenosine Chemical compound C1=NC=2C(N)=NC=NC=2N1[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O OIRDTQYFTABQOQ-KQYNXXCUSA-N 0.000 description 8
- 238000004458 analytical method Methods 0.000 description 8
- 230000008878 coupling Effects 0.000 description 8
- 238000010168 coupling process Methods 0.000 description 8
- 238000005859 coupling reaction Methods 0.000 description 8
- 230000002950 deficient Effects 0.000 description 8
- 238000010348 incorporation Methods 0.000 description 8
- AHCYMLUZIRLXAA-SHYZEUOFSA-N Deoxyuridine 5'-triphosphate Chemical compound O1[C@H](COP(O)(=O)OP(O)(=O)OP(O)(O)=O)[C@@H](O)C[C@@H]1N1C(=O)NC(=O)C=C1 AHCYMLUZIRLXAA-SHYZEUOFSA-N 0.000 description 7
- 108060002716 Exonuclease Proteins 0.000 description 7
- 108010002747 Pfu DNA polymerase Proteins 0.000 description 7
- 230000009471 action Effects 0.000 description 7
- 239000006227 byproduct Substances 0.000 description 7
- 238000005251 capillar electrophoresis Methods 0.000 description 7
- RGWHQCVHVJXOKC-SHYZEUOFSA-J dCTP(4-) Chemical compound O=C1N=C(N)C=CN1[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OP([O-])([O-])=O)[C@@H](O)C1 RGWHQCVHVJXOKC-SHYZEUOFSA-J 0.000 description 7
- 239000000539 dimer Substances 0.000 description 7
- 102000013165 exonuclease Human genes 0.000 description 7
- 238000009396 hybridization Methods 0.000 description 7
- 238000005259 measurement Methods 0.000 description 7
- 125000004573 morpholin-4-yl group Chemical group N1(CCOCC1)* 0.000 description 7
- 230000002829 reductive effect Effects 0.000 description 7
- 102000004190 Enzymes Human genes 0.000 description 6
- 108090000790 Enzymes Proteins 0.000 description 6
- ISAKRJDGNUQOIC-UHFFFAOYSA-N Uracil Chemical compound O=C1C=CNC(=O)N1 ISAKRJDGNUQOIC-UHFFFAOYSA-N 0.000 description 6
- OPTASPLRGRRNAP-UHFFFAOYSA-N cytosine Chemical compound NC=1C=CNC(=O)N=1 OPTASPLRGRRNAP-UHFFFAOYSA-N 0.000 description 6
- SUYVUBYJARFZHO-RRKCRQDMSA-N dATP Chemical compound C1=NC=2C(N)=NC=NC=2N1[C@H]1C[C@H](O)[C@@H](COP(O)(=O)OP(O)(=O)OP(O)(O)=O)O1 SUYVUBYJARFZHO-RRKCRQDMSA-N 0.000 description 6
- SUYVUBYJARFZHO-UHFFFAOYSA-N dATP Natural products C1=NC=2C(N)=NC=NC=2N1C1CC(O)C(COP(O)(=O)OP(O)(=O)OP(O)(O)=O)O1 SUYVUBYJARFZHO-UHFFFAOYSA-N 0.000 description 6
- HAAZLUGHYHWQIW-KVQBGUIXSA-N dGTP Chemical compound C1=NC=2C(=O)NC(N)=NC=2N1[C@H]1C[C@H](O)[C@@H](COP(O)(=O)OP(O)(=O)OP(O)(O)=O)O1 HAAZLUGHYHWQIW-KVQBGUIXSA-N 0.000 description 6
- IIRDTKBZINWQAW-UHFFFAOYSA-N hexaethylene glycol Chemical group OCCOCCOCCOCCOCCOCCO IIRDTKBZINWQAW-UHFFFAOYSA-N 0.000 description 6
- 239000013642 negative control Substances 0.000 description 6
- 102100022524 Alpha-1-antichymotrypsin Human genes 0.000 description 5
- NYHBQMYGNKIUIF-UUOKFMHZSA-N Guanosine Chemical compound C1=NC=2C(=O)NC(N)=NC=2N1[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O NYHBQMYGNKIUIF-UUOKFMHZSA-N 0.000 description 5
- 101000678026 Homo sapiens Alpha-1-antichymotrypsin Proteins 0.000 description 5
- 125000000217 alkyl group Chemical group 0.000 description 5
- 239000011616 biotin Substances 0.000 description 5
- 229960002685 biotin Drugs 0.000 description 5
- 235000020958 biotin Nutrition 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- NHVNXKFIZYSCEB-XLPZGREQSA-N dTTP Chemical compound O=C1NC(=O)C(C)=CN1[C@@H]1O[C@H](COP(O)(=O)OP(O)(=O)OP(O)(O)=O)[C@@H](O)C1 NHVNXKFIZYSCEB-XLPZGREQSA-N 0.000 description 5
- 230000003247 decreasing effect Effects 0.000 description 5
- 239000003999 initiator Substances 0.000 description 5
- 239000002126 C01EB10 - Adenosine Substances 0.000 description 4
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 4
- ZHNUHDYFZUAESO-UHFFFAOYSA-N Formamide Chemical compound NC=O ZHNUHDYFZUAESO-UHFFFAOYSA-N 0.000 description 4
- UGQMRVRMYYASKQ-KQYNXXCUSA-N Inosine Chemical class O[C@@H]1[C@H](O)[C@@H](CO)O[C@H]1N1C2=NC=NC(O)=C2N=C1 UGQMRVRMYYASKQ-KQYNXXCUSA-N 0.000 description 4
- 108020005187 Oligonucleotide Probes Proteins 0.000 description 4
- 108010001244 Tli polymerase Proteins 0.000 description 4
- 238000007792 addition Methods 0.000 description 4
- 229960005305 adenosine Drugs 0.000 description 4
- 230000015556 catabolic process Effects 0.000 description 4
- 150000001768 cations Chemical class 0.000 description 4
- 238000006731 degradation reaction Methods 0.000 description 4
- 230000003111 delayed effect Effects 0.000 description 4
- 239000007850 fluorescent dye Substances 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000011534 incubation Methods 0.000 description 4
- 230000010354 integration Effects 0.000 description 4
- 239000000543 intermediate Substances 0.000 description 4
- 230000000670 limiting effect Effects 0.000 description 4
- 230000004807 localization Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 108020004999 messenger RNA Proteins 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000002751 oligonucleotide probe Substances 0.000 description 4
- UEZVMMHDMIWARA-UHFFFAOYSA-M phosphonate Chemical group [O-]P(=O)=O UEZVMMHDMIWARA-UHFFFAOYSA-M 0.000 description 4
- 230000037452 priming Effects 0.000 description 4
- 230000001915 proofreading effect Effects 0.000 description 4
- 102000004169 proteins and genes Human genes 0.000 description 4
- 238000003753 real-time PCR Methods 0.000 description 4
- 230000000087 stabilizing effect Effects 0.000 description 4
- ABZLKHKQJHEPAX-UHFFFAOYSA-N tetramethylrhodamine Chemical compound C=12C=CC(N(C)C)=CC2=[O+]C2=CC(N(C)C)=CC=C2C=1C1=CC=CC=C1C([O-])=O ABZLKHKQJHEPAX-UHFFFAOYSA-N 0.000 description 4
- ZDTFMPXQUSBYRL-UUOKFMHZSA-N 2-Aminoadenosine Chemical class C12=NC(N)=NC(N)=C2N=CN1[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O ZDTFMPXQUSBYRL-UUOKFMHZSA-N 0.000 description 3
- QKNYBSVHEMOAJP-UHFFFAOYSA-N 2-amino-2-(hydroxymethyl)propane-1,3-diol;hydron;chloride Chemical compound Cl.OCC(N)(CO)CO QKNYBSVHEMOAJP-UHFFFAOYSA-N 0.000 description 3
- 125000004200 2-methoxyethyl group Chemical group [H]C([H])([H])OC([H])([H])C([H])([H])* 0.000 description 3
- 210000002925 A-like Anatomy 0.000 description 3
- 208000035657 Abasia Diseases 0.000 description 3
- MIKUYHXYGGJMLM-GIMIYPNGSA-N Crotonoside Natural products C1=NC2=C(N)NC(=O)N=C2N1[C@H]1O[C@@H](CO)[C@H](O)[C@@H]1O MIKUYHXYGGJMLM-GIMIYPNGSA-N 0.000 description 3
- NYHBQMYGNKIUIF-UHFFFAOYSA-N D-guanosine Natural products C1=2NC(N)=NC(=O)C=2N=CN1C1OC(CO)C(O)C1O NYHBQMYGNKIUIF-UHFFFAOYSA-N 0.000 description 3
- HMFHBZSHGGEWLO-SOOFDHNKSA-N D-ribofuranose Chemical compound OC[C@H]1OC(O)[C@H](O)[C@@H]1O HMFHBZSHGGEWLO-SOOFDHNKSA-N 0.000 description 3
- 108010017826 DNA Polymerase I Proteins 0.000 description 3
- 102000004594 DNA Polymerase I Human genes 0.000 description 3
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 3
- 102100031780 Endonuclease Human genes 0.000 description 3
- 229930010555 Inosine Natural products 0.000 description 3
- 229910019142 PO4 Inorganic materials 0.000 description 3
- 108091028664 Ribonucleotide Proteins 0.000 description 3
- PYMYPHUHKUWMLA-LMVFSUKVSA-N Ribose Natural products OC[C@@H](O)[C@@H](O)[C@@H](O)C=O PYMYPHUHKUWMLA-LMVFSUKVSA-N 0.000 description 3
- 241000239226 Scorpiones Species 0.000 description 3
- 239000012190 activator Substances 0.000 description 3
- HMFHBZSHGGEWLO-UHFFFAOYSA-N alpha-D-Furanose-Ribose Natural products OCC1OC(O)C(O)C1O HMFHBZSHGGEWLO-UHFFFAOYSA-N 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 239000007853 buffer solution Substances 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 3
- 238000006555 catalytic reaction Methods 0.000 description 3
- 230000009918 complex formation Effects 0.000 description 3
- 238000011109 contamination Methods 0.000 description 3
- 125000004122 cyclic group Chemical group 0.000 description 3
- 229940104302 cytosine Drugs 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000004069 differentiation Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000005284 excitation Effects 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- GNBHRKFJIUUOQI-UHFFFAOYSA-N fluorescein Chemical compound O1C(=O)C2=CC=CC=C2C21C1=CC=C(O)C=C1OC1=CC(O)=CC=C21 GNBHRKFJIUUOQI-UHFFFAOYSA-N 0.000 description 3
- 238000012252 genetic analysis Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 230000001939 inductive effect Effects 0.000 description 3
- 230000005764 inhibitory process Effects 0.000 description 3
- 229960003786 inosine Drugs 0.000 description 3
- 239000003550 marker Substances 0.000 description 3
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 3
- 238000007479 molecular analysis Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 239000010452 phosphate Substances 0.000 description 3
- 125000002467 phosphate group Chemical group [H]OP(=O)(O[H])O[*] 0.000 description 3
- 102000054765 polymorphisms of proteins Human genes 0.000 description 3
- 230000000644 propagated effect Effects 0.000 description 3
- 239000000376 reactant Substances 0.000 description 3
- 108091008146 restriction endonucleases Proteins 0.000 description 3
- 238000012552 review Methods 0.000 description 3
- 239000002336 ribonucleotide Substances 0.000 description 3
- 238000007480 sanger sequencing Methods 0.000 description 3
- 125000006850 spacer group Chemical group 0.000 description 3
- 238000010561 standard procedure Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 229940035893 uracil Drugs 0.000 description 3
- JCLFHZLOKITRCE-UHFFFAOYSA-N 4-pentoxyphenol Chemical compound CCCCCOC1=CC=C(O)C=C1 JCLFHZLOKITRCE-UHFFFAOYSA-N 0.000 description 2
- OZFPSOBLQZPIAV-UHFFFAOYSA-N 5-nitro-1h-indole Chemical class [O-][N+](=O)C1=CC=C2NC=CC2=C1 OZFPSOBLQZPIAV-UHFFFAOYSA-N 0.000 description 2
- MSSXOMSJDRHRMC-UHFFFAOYSA-N 9H-purine-2,6-diamine Chemical compound NC1=NC(N)=C2NC=NC2=N1 MSSXOMSJDRHRMC-UHFFFAOYSA-N 0.000 description 2
- 241000251468 Actinopterygii Species 0.000 description 2
- 241000972773 Aulopiformes Species 0.000 description 2
- 230000008836 DNA modification Effects 0.000 description 2
- SHIBSTMRCDJXLN-UHFFFAOYSA-N Digoxigenin Natural products C1CC(C2C(C3(C)CCC(O)CC3CC2)CC2O)(O)C2(C)C1C1=CC(=O)OC1 SHIBSTMRCDJXLN-UHFFFAOYSA-N 0.000 description 2
- 108060004795 Methyltransferase Proteins 0.000 description 2
- 241000713869 Moloney murine leukemia virus Species 0.000 description 2
- PKFBJSDMCRJYDC-GEZSXCAASA-N N-acetyl-s-geranylgeranyl-l-cysteine Chemical compound CC(C)=CCC\C(C)=C\CC\C(C)=C\CC\C(C)=C\CSC[C@@H](C(O)=O)NC(C)=O PKFBJSDMCRJYDC-GEZSXCAASA-N 0.000 description 2
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 2
- 108091093037 Peptide nucleic acid Proteins 0.000 description 2
- 108010092799 RNA-directed DNA polymerase Proteins 0.000 description 2
- DRTQHJPVMGBUCF-XVFCMESISA-N Uridine Chemical compound O[C@@H]1[C@H](O)[C@@H](CO)O[C@H]1N1C(=O)NC(=O)C=C1 DRTQHJPVMGBUCF-XVFCMESISA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 230000004075 alteration Effects 0.000 description 2
- 238000002820 assay format Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000003776 cleavage reaction Methods 0.000 description 2
- 239000002299 complementary DNA Substances 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000004925 denaturation Methods 0.000 description 2
- 230000036425 denaturation Effects 0.000 description 2
- 239000005547 deoxyribonucleotide Substances 0.000 description 2
- 125000002637 deoxyribonucleotide group Chemical group 0.000 description 2
- QONQRTHLHBTMGP-UHFFFAOYSA-N digitoxigenin Natural products CC12CCC(C3(CCC(O)CC3CC3)C)C3C11OC1CC2C1=CC(=O)OC1 QONQRTHLHBTMGP-UHFFFAOYSA-N 0.000 description 2
- SHIBSTMRCDJXLN-KCZCNTNESA-N digoxigenin Chemical compound C1([C@@H]2[C@@]3([C@@](CC2)(O)[C@H]2[C@@H]([C@@]4(C)CC[C@H](O)C[C@H]4CC2)C[C@H]3O)C)=CC(=O)OC1 SHIBSTMRCDJXLN-KCZCNTNESA-N 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- WDRWZVWLVBXVOI-QTNFYWBSSA-L dipotassium;(2s)-2-aminopentanedioate Chemical compound [K+].[K+].[O-]C(=O)[C@@H](N)CCC([O-])=O WDRWZVWLVBXVOI-QTNFYWBSSA-L 0.000 description 2
- 238000001962 electrophoresis Methods 0.000 description 2
- 230000008030 elimination Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 108010091897 factor V Leiden Proteins 0.000 description 2
- 235000019688 fish Nutrition 0.000 description 2
- 239000003112 inhibitor Substances 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 230000009545 invasion Effects 0.000 description 2
- DRAVOWXCEBXPTN-UHFFFAOYSA-N isoguanine Chemical compound NC1=NC(=O)NC2=C1NC=N2 DRAVOWXCEBXPTN-UHFFFAOYSA-N 0.000 description 2
- 238000002372 labelling Methods 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000011880 melting curve analysis Methods 0.000 description 2
- 238000002493 microarray Methods 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 235000013919 monopotassium glutamate Nutrition 0.000 description 2
- 238000007481 next generation sequencing Methods 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical group [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 230000002028 premature Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000000750 progressive effect Effects 0.000 description 2
- 125000002652 ribonucleotide group Chemical group 0.000 description 2
- 235000019515 salmon Nutrition 0.000 description 2
- 230000007017 scission Effects 0.000 description 2
- 238000012772 sequence design Methods 0.000 description 2
- 238000011895 specific detection Methods 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 238000004454 trace mineral analysis Methods 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- HDTRYLNUVZCQOY-UHFFFAOYSA-N α-D-glucopyranosyl-α-D-glucopyranoside Natural products OC1C(O)C(O)C(CO)OC1OC1C(O)C(O)C(O)C(CO)O1 HDTRYLNUVZCQOY-UHFFFAOYSA-N 0.000 description 1
- GZEFTKHSACGIBG-UGKPPGOTSA-N 1-[(2r,3r,4s,5r)-3,4-dihydroxy-5-(hydroxymethyl)-2-propyloxolan-2-yl]pyrimidine-2,4-dione Chemical compound C1=CC(=O)NC(=O)N1[C@]1(CCC)O[C@H](CO)[C@@H](O)[C@H]1O GZEFTKHSACGIBG-UGKPPGOTSA-N 0.000 description 1
- OQQSPLKQMINFTG-TURQNECASA-N 1-[(2r,3r,4s,5r)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-5-prop-2-ynylpyrimidine-2,4-dione Chemical compound O[C@@H]1[C@H](O)[C@@H](CO)O[C@H]1N1C(=O)NC(=O)C(CC#C)=C1 OQQSPLKQMINFTG-TURQNECASA-N 0.000 description 1
- PIINGYXNCHTJTF-UHFFFAOYSA-N 2-(2-azaniumylethylamino)acetate Chemical compound NCCNCC(O)=O PIINGYXNCHTJTF-UHFFFAOYSA-N 0.000 description 1
- JKMHFZQWWAIEOD-UHFFFAOYSA-N 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid Chemical compound OCC[NH+]1CCN(CCS([O-])(=O)=O)CC1 JKMHFZQWWAIEOD-UHFFFAOYSA-N 0.000 description 1
- JRYMOPZHXMVHTA-DAGMQNCNSA-N 2-amino-7-[(2r,3r,4s,5r)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1h-pyrrolo[2,3-d]pyrimidin-4-one Chemical compound C1=CC=2C(=O)NC(N)=NC=2N1[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O JRYMOPZHXMVHTA-DAGMQNCNSA-N 0.000 description 1
- 150000005019 2-aminopurines Chemical class 0.000 description 1
- HCGYMSSYSAKGPK-UHFFFAOYSA-N 2-nitro-1h-indole Chemical compound C1=CC=C2NC([N+](=O)[O-])=CC2=C1 HCGYMSSYSAKGPK-UHFFFAOYSA-N 0.000 description 1
- 125000001494 2-propynyl group Chemical group [H]C#CC([H])([H])* 0.000 description 1
- GJTBSTBJLVYKAU-XVFCMESISA-N 2-thiouridine Chemical class O[C@@H]1[C@H](O)[C@@H](CO)O[C@H]1N1C(=S)NC(=O)C=C1 GJTBSTBJLVYKAU-XVFCMESISA-N 0.000 description 1
- FWMNVWWHGCHHJJ-SKKKGAJSSA-N 4-amino-1-[(2r)-6-amino-2-[[(2r)-2-[[(2r)-2-[[(2r)-2-amino-3-phenylpropanoyl]amino]-3-phenylpropanoyl]amino]-4-methylpentanoyl]amino]hexanoyl]piperidine-4-carboxylic acid Chemical compound C([C@H](C(=O)N[C@H](CC(C)C)C(=O)N[C@H](CCCCN)C(=O)N1CCC(N)(CC1)C(O)=O)NC(=O)[C@H](N)CC=1C=CC=CC=1)C1=CC=CC=C1 FWMNVWWHGCHHJJ-SKKKGAJSSA-N 0.000 description 1
- LRSASMSXMSNRBT-UHFFFAOYSA-N 5-methylcytosine Chemical class CC1=CNC(=O)N=C1N LRSASMSXMSNRBT-UHFFFAOYSA-N 0.000 description 1
- OJPWPQVMVIQVRH-UHFFFAOYSA-N 6-amino-5-propyl-1h-pyrimidin-2-one Chemical compound CCCC1=CNC(=O)N=C1N OJPWPQVMVIQVRH-UHFFFAOYSA-N 0.000 description 1
- HDZZVAMISRMYHH-UHFFFAOYSA-N 9beta-Ribofuranosyl-7-deazaadenin Natural products C1=CC=2C(N)=NC=NC=2N1C1OC(CO)C(O)C1O HDZZVAMISRMYHH-UHFFFAOYSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 108091093088 Amplicon Proteins 0.000 description 1
- 108091023037 Aptamer Proteins 0.000 description 1
- KWIUHFFTVRNATP-UHFFFAOYSA-N Betaine Natural products C[N+](C)(C)CC([O-])=O KWIUHFFTVRNATP-UHFFFAOYSA-N 0.000 description 1
- 101000983970 Conus catus Alpha-conotoxin CIB Proteins 0.000 description 1
- 125000000824 D-ribofuranosyl group Chemical group [H]OC([H])([H])[C@@]1([H])OC([H])(*)[C@]([H])(O[H])[C@]1([H])O[H] 0.000 description 1
- 230000004568 DNA-binding Effects 0.000 description 1
- 108010042407 Endonucleases Proteins 0.000 description 1
- 108010014172 Factor V Proteins 0.000 description 1
- 206010058279 Factor V Leiden mutation Diseases 0.000 description 1
- 239000004606 Fillers/Extenders Substances 0.000 description 1
- 239000007995 HEPES buffer Substances 0.000 description 1
- 101001027836 Homo sapiens Coagulation factor V Proteins 0.000 description 1
- 101001122597 Homo sapiens Ribonuclease P protein subunit p20 Proteins 0.000 description 1
- WHUUTDBJXJRKMK-VKHMYHEASA-N L-glutamic acid Chemical compound OC(=O)[C@@H](N)CCC(O)=O WHUUTDBJXJRKMK-VKHMYHEASA-N 0.000 description 1
- 108700011259 MicroRNAs Proteins 0.000 description 1
- 208000032818 Microsatellite Instability Diseases 0.000 description 1
- KWIUHFFTVRNATP-UHFFFAOYSA-O N,N,N-trimethylglycinium Chemical compound C[N+](C)(C)CC(O)=O KWIUHFFTVRNATP-UHFFFAOYSA-O 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- 206010029719 Nonspecific reaction Diseases 0.000 description 1
- 239000008118 PEG 6000 Substances 0.000 description 1
- 229920002584 Polyethylene Glycol 6000 Polymers 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 229920001213 Polysorbate 20 Polymers 0.000 description 1
- 108010029485 Protein Isoforms Proteins 0.000 description 1
- 102000001708 Protein Isoforms Human genes 0.000 description 1
- 102000018120 Recombinases Human genes 0.000 description 1
- 108010091086 Recombinases Proteins 0.000 description 1
- 102100028674 Ribonuclease P protein subunit p20 Human genes 0.000 description 1
- 238000012300 Sequence Analysis Methods 0.000 description 1
- 108010090804 Streptavidin Proteins 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- RZCIEJXAILMSQK-JXOAFFINSA-N TTP Chemical compound O=C1NC(=O)C(C)=CN1[C@H]1[C@H](O)[C@H](O)[C@@H](COP(O)(=O)OP(O)(=O)OP(O)(O)=O)O1 RZCIEJXAILMSQK-JXOAFFINSA-N 0.000 description 1
- HDTRYLNUVZCQOY-WSWWMNSNSA-N Trehalose Natural products O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@@H]1O[C@@H]1[C@H](O)[C@@H](O)[C@@H](O)[C@@H](CO)O1 HDTRYLNUVZCQOY-WSWWMNSNSA-N 0.000 description 1
- 239000013504 Triton X-100 Substances 0.000 description 1
- 229920004890 Triton X-100 Polymers 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- GFFGJBXGBJISGV-UHFFFAOYSA-N adenyl group Chemical group N1=CN=C2N=CNC2=C1N GFFGJBXGBJISGV-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- HDTRYLNUVZCQOY-LIZSDCNHSA-N alpha,alpha-trehalose Chemical compound O[C@@H]1[C@@H](O)[C@H](O)[C@@H](CO)O[C@@H]1O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 HDTRYLNUVZCQOY-LIZSDCNHSA-N 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000037429 base substitution Effects 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- DRTQHJPVMGBUCF-PSQAKQOGSA-N beta-L-uridine Natural products O[C@H]1[C@@H](O)[C@H](CO)O[C@@H]1N1C(=O)NC(=O)C=C1 DRTQHJPVMGBUCF-PSQAKQOGSA-N 0.000 description 1
- 229960003237 betaine Drugs 0.000 description 1
- 230000003115 biocidal effect Effects 0.000 description 1
- 239000012620 biological material Substances 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 201000011510 cancer Diseases 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 125000003636 chemical group Chemical group 0.000 description 1
- 238000010367 cloning Methods 0.000 description 1
- 230000009137 competitive binding Effects 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000001687 destabilization Effects 0.000 description 1
- 230000000368 destabilizing effect Effects 0.000 description 1
- 238000002405 diagnostic procedure Methods 0.000 description 1
- 239000005546 dideoxynucleotide Substances 0.000 description 1
- 238000012850 discrimination method Methods 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- PXEDJBXQKAGXNJ-QTNFYWBSSA-L disodium L-glutamate Chemical compound [Na+].[Na+].[O-]C(=O)[C@@H](N)CCC([O-])=O PXEDJBXQKAGXNJ-QTNFYWBSSA-L 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- DEFVIWRASFVYLL-UHFFFAOYSA-N ethylene glycol bis(2-aminoethyl)tetraacetic acid Chemical compound OC(=O)CN(CC(O)=O)CCOCCOCCN(CC(O)=O)CC(O)=O DEFVIWRASFVYLL-UHFFFAOYSA-N 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 230000004077 genetic alteration Effects 0.000 description 1
- 231100000118 genetic alteration Toxicity 0.000 description 1
- 229930195712 glutamate Natural products 0.000 description 1
- 229940049906 glutamate Drugs 0.000 description 1
- 150000002334 glycols Chemical class 0.000 description 1
- UYTPUPDQBNUYGX-UHFFFAOYSA-N guanine Chemical class O=C1NC(N)=NC2=C1N=CN2 UYTPUPDQBNUYGX-UHFFFAOYSA-N 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000011528 liquid biopsy Methods 0.000 description 1
- UEGPKNKPLBYCNK-UHFFFAOYSA-L magnesium acetate Chemical compound [Mg+2].CC([O-])=O.CC([O-])=O UEGPKNKPLBYCNK-UHFFFAOYSA-L 0.000 description 1
- 229940069446 magnesium acetate Drugs 0.000 description 1
- 235000011285 magnesium acetate Nutrition 0.000 description 1
- 239000011654 magnesium acetate Substances 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000002679 microRNA Substances 0.000 description 1
- 238000010369 molecular cloning Methods 0.000 description 1
- 235000013923 monosodium glutamate Nutrition 0.000 description 1
- 238000002703 mutagenesis Methods 0.000 description 1
- 231100000350 mutagenesis Toxicity 0.000 description 1
- 238000001668 nucleic acid synthesis Methods 0.000 description 1
- 238000002515 oligonucleotide synthesis Methods 0.000 description 1
- 238000005580 one pot reaction Methods 0.000 description 1
- 230000002688 persistence Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 239000000256 polyoxyethylene sorbitan monolaurate Substances 0.000 description 1
- 235000010486 polyoxyethylene sorbitan monolaurate Nutrition 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 239000011535 reaction buffer Substances 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000010517 secondary reaction Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000002864 sequence alignment Methods 0.000 description 1
- 238000012163 sequencing technique Methods 0.000 description 1
- 229940073490 sodium glutamate Drugs 0.000 description 1
- 238000010532 solid phase synthesis reaction Methods 0.000 description 1
- 108010068698 spleen exonuclease Proteins 0.000 description 1
- 230000008093 supporting effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- FBEVECUEMUUFKM-UHFFFAOYSA-M tetrapropylazanium;chloride Chemical compound [Cl-].CCC[N+](CCC)(CCC)CCC FBEVECUEMUUFKM-UHFFFAOYSA-M 0.000 description 1
- RWQNBRDOKXIBIV-UHFFFAOYSA-N thymine Chemical class CC1=CNC(=O)NC1=O RWQNBRDOKXIBIV-UHFFFAOYSA-N 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
- 238000012549 training Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- PIEPQKCYPFFYMG-UHFFFAOYSA-N tris acetate Chemical compound CC(O)=O.OCC(N)(CO)CO PIEPQKCYPFFYMG-UHFFFAOYSA-N 0.000 description 1
- GPRLSGONYQIRFK-MNYXATJNSA-N triton Chemical compound [3H+] GPRLSGONYQIRFK-MNYXATJNSA-N 0.000 description 1
- HDZZVAMISRMYHH-KCGFPETGSA-N tubercidin Chemical compound C1=CC=2C(N)=NC=NC=2N1[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O HDZZVAMISRMYHH-KCGFPETGSA-N 0.000 description 1
- DRTQHJPVMGBUCF-UHFFFAOYSA-N uracil arabinoside Natural products OC1C(O)C(CO)OC1N1C(=O)NC(=O)C=C1 DRTQHJPVMGBUCF-UHFFFAOYSA-N 0.000 description 1
- 229940045145 uridine Drugs 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/68—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
- C12Q1/6844—Nucleic acid amplification reactions
- C12Q1/6848—Nucleic acid amplification reactions characterised by the means for preventing contamination or increasing the specificity or sensitivity of an amplification reaction
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/68—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving nucleic acids
- C12Q1/6844—Nucleic acid amplification reactions
- C12Q1/6853—Nucleic acid amplification reactions using modified primers or templates
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2525/00—Reactions involving modified oligonucleotides, nucleic acids, or nucleotides
- C12Q2525/10—Modifications characterised by
- C12Q2525/113—Modifications characterised by incorporating modified backbone
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2525/00—Reactions involving modified oligonucleotides, nucleic acids, or nucleotides
- C12Q2525/10—Modifications characterised by
- C12Q2525/121—Modifications characterised by incorporating both deoxyribonucleotides and ribonucleotides
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2525/00—Reactions involving modified oligonucleotides, nucleic acids, or nucleotides
- C12Q2525/10—Modifications characterised by
- C12Q2525/125—Modifications characterised by incorporating agents resulting in resistance to degradation
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2525/00—Reactions involving modified oligonucleotides, nucleic acids, or nucleotides
- C12Q2525/10—Modifications characterised by
- C12Q2525/161—Modifications characterised by incorporating target specific and non-target specific sites
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2525/00—Reactions involving modified oligonucleotides, nucleic acids, or nucleotides
- C12Q2525/10—Modifications characterised by
- C12Q2525/186—Modifications characterised by incorporating a non-extendable or blocking moiety
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2525/00—Reactions involving modified oligonucleotides, nucleic acids, or nucleotides
- C12Q2525/10—Modifications characterised by
- C12Q2525/204—Modifications characterised by specific length of the oligonucleotides
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2537/00—Reactions characterised by the reaction format or use of a specific feature
- C12Q2537/10—Reactions characterised by the reaction format or use of a specific feature the purpose or use of
- C12Q2537/161—A competitive reaction step
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q2537/00—Reactions characterised by the reaction format or use of a specific feature
- C12Q2537/10—Reactions characterised by the reaction format or use of a specific feature the purpose or use of
- C12Q2537/163—Reactions characterised by the reaction format or use of a specific feature the purpose or use of blocking probe
Definitions
- the present invention relates to a method for the template-dependent primer extension reaction by means of a template-dependent polymerase.
- primer extension products can be prepared which can be used in an amplification of nucleic acids.
- the method may thus help to improve the specificity of analyzes involving a primer extension step.
- the primer extension reaction plays a role in many genetic analyzes, e.g. in amplification methods, such as PCR, or in individual steps of the analyzes.
- An enzymatic primer extension is carried out by means of a polymerase, whereby a synthesized strand is formed. In many processes, this strand is detached from the template by various means, independently of the sequence, and used in further process steps.
- agents include, for example, temperature or denaturing agents such as alkalis or formamide.
- strands can be separated by enzymes using chemical energy sources such as dNTP or ATP. These include helicases or polymerases with strand-displacing action. Such separations are predominantly sequence-unspecific.
- the availability of free complementary positions may play a role in potential interactions with other reaction components in many processes.
- the frequency and duration of binding of reactants to each other via complementary positions may be one Play role for the speed or yield of a certain reaction step.
- Many reactions in the field of molecular analysis are based on the creation of more or less stable bonds between individual reaction components. The effects achieved can have an influence on the specificity of reactions.
- Primer extension is used in many genetic analyzes.
- the result of a correct priming formation of a primer-template complex
- the continuation of the template-dependent enzymatic synthesis by means of a polymerase plays a role.
- primer extension product the product of a sequence-specific primer extension reaction (primer extension product)
- the synthesis phase is complete.
- the primer extension product can be detached from the template and used in other procedures.
- both the synthesis of the primer extension product per se and the provision of the synthesized primer extension product can be improved to a further use.
- the primer extension reaction is currently optimized in most cases by adjusting the primer binding (eg, by using optimal reaction temperatures, buffer conditions and complementarity of the primers to a primer binding site).
- Some tools have been developed to improve primer binding. These are limited only to the improvement of primer binding and do not go beyond the primer length.
- Using a polymerase with 3 ' exonuclease activity polymerases with proofreading) one can achieve a further improvement in the quality of the synthesis result.
- the 3 ' end of the synthesized strand is checked by polymerase-associated exonuclease.
- primer extension reaction (priming and proofreading by the polymerase), in most cases the primer extension reaction is not further evaluated for quality.
- a method for extension of a primer oligonucleotide comprises the steps ( Figures 1, 2):
- Nucleic acid chain (M1) wherein the primer oligonucleotide (P1 .1) comprises the following ranges: a first region, essentially sequence-specific, to a
- complementary segment comprising a portion of the target sequence can bind within a provided nucleic acid chain (M1),
- a second region (overhang) connected to the 5 'end of the first region or connected via a linker, which second region can be bound by a controller oligonucleotide (C1 .1); c) extension of the primer oligonucleotide (P.1.1) by a template-dependent polymerase to give a primer extension product (primer extension product, P1 .1 -Ext) which has a synthesized region in addition to the primer oligonucleotide (P1.1) which is substantially complementary to a nucleic acid chain comprising a target sequence (M1), wherein the primer extension product (P1 .1 -Ext) and the nucleic acid chain (M1) form a double strand under reaction conditions;
- controller oligonucleotide (C1.1) binding of a controller oligonucleotide (C1.1) to the primer extension product (P1.1-Tex), wherein the controller oligonucleotide (C1.1) comprises the following ranges:
- controller oligonucleotide (C1 .1) does not serve as a template for a primer extension of the primer oligonucleotide (P1 .1) and the controller oligonucleotide (C1 .1) with its first, second and third regions to the primer extension product (P1 1 -Ext) with displacement of complementary segments of the nucleic acid chain (M1) can bind.
- the second region of the primer oligonucleotide is in particular a polynucleotide tail.
- essentially sequence-specific in the context of the invention means in particular that the mutually complementary regions of the primer oligonucleotide and the nucleic acid to be amplified have not more than 5, 4, 3, 2, or 1 mismatches.
- substantially complementary in the sense of the invention means in particular that the mutually complementary regions of nucleic acids have not more than 5, 4, 3, 2, or 1 mismatches.
- primer oligonucleotides and controller oligonucleotide are present at the beginning of the reaction. However, sequential addition of individual reagents is also possible.
- PCR e.g., first carried out for 1 to 10 cycles and then further, for example, under isothermal conditions.
- the first region of the primer oligonucleotide is completely sequence-specific, i. in particular without mismatches, to which the nucleic acid to be amplified can bind.
- the second region (overhang) of the primer oligonucleotide remains essentially uncoupled from a polymerase used for the primer extension under the chosen reaction conditions.
- the method further comprises the following step: hybridizing a block oligonucleotide to a region of the nucleic acid chain comprising a target sequence
- Temporative strand located in the 5 ' direction of the region bound by the first region (primer binding site) of the primer oligonucleotide, the block oligonucleotide being designed to inhibit extension of the primer oligonucleotide at the bound region to block.
- the block oligonucleotide is characterized by a length of about 15 nucleotides to about 60 nucleotides, and optionally modifications (eg PTO or LNA (locked nucleic acid, 2 ⁇ , 4'C methylenverb Wegte ribosyl residues in the polymer) or PNA (peptide nucleic acid, N- (2-aminoethyl) glycine backbone).
- PTO or LNA locked nucleic acid, 2 ⁇ , 4'C methylenverb Wegte ribosyl residues in the polymer
- PNA peptide nucleic acid, N- (2-aminoethyl) glycine backbone
- the third region of the controller oligonucleotide is substantially complementary to the part of the synthesized region of the primer extension product which directly adjoins the primer oligonucleotide portion of the primer extension product.
- this improves the sequence-specific displacement of the nucleic acid to be amplified.
- the portion of the synthesized region that is substantially complementary to the third region of the controller nucleotide has a length in the range of 5 nucleotides to 50 nucleotides.
- the part of the synthesized region which is substantially complementary to the third region of the controller nucleotide has a length in the range from 3 nucleotides to 70 nucleotides, in particular 5 nucleotides to 50 nucleotides, in particular 5 nucleotides to 50 Nucleotides, in particular 5 nucleotides to 30 nucleotides, in particular 5 nucleotides to 20 nucleotides.
- the method further comprises the step of: hybridizing a probe to a portion of the primer extension product that is not bound by the controller oligonucleotide.
- the method is carried out essentially isothermally.
- substantially isothermal in the sense of the present description means in particular that the reaction temperature is carried out within a temperature range of 10 K temperature difference between the highest and the lowest temperature.
- the target sequence of a nucleic acid has a length in the range from about 20 nucleotides to about 300 nucleotides.
- the primer oligonucleotide has a length in the range of 15 nucleotides to 100 nucleotides.
- the controller oligonucleotide has a length in the range from 20 nucleotides to 100 nucleotides.
- the chosen reaction conditions comprise a reaction temperature in the range from 50 ° C to 70 ° C.
- the primer oligonucleotide has one or more modifications in the second region, in particular immediately following the first region of the primer oligonucleotide (FIG. 26), which stops the polymerase used at the second region ,
- the primer oligonucleotide has one or more modifications in the second region, in particular immediately following the first region of the primer oligonucleotide (FIG. 26), which stops the polymerase used at the second region .
- the first region of the primer oligonucleotide is optionally amplified in later process steps.
- nucleotide modifications which, although capable of complementary binding to the primer extension product, are not accepted by the polymerase as a template.
- nucleotide Modifications provide nucleotide compounds with modified phosphate-sugar backbone units, for example 2 '-0-alkyl-RNA modifications (eg 2' OMe), LNA modifications or morpholino modifications. The presence of such modifications in a strand prevents a DNA dependent polymerase reading such a strand. The number of such modifications may be different, usually few modifications (between 1 and 20) may be sufficient to prevent a polymerase from reading such a strand.
- nucleotide modifications can be used, for example, at or around the binding site of the primer oligonucleotide to the controller oligonucleotide and / or as constituents of the second region of the primer oligonucleotide.
- the second primer region is uncopiable only in one of several alternative embodiments. This embodiment allows, for example, the use of identical primers in the primer extension and in an optionally subsequent amplification.
- primers must have a "protection". This may consist of a "first blocking unit” before the second area or the entire second area consists of modifications that are uncopiable.
- this second primer region can be quite copiable when using long matrices (see FIGS. 1-3), since the 3 ' end of the template is not immediately in front of the second region and thus can not prime a synthesis.
- the primer extension primer can not be used as an amplification primer.
- the second region is not allowed to bind to the template and thus is present for the interaction with the controller single-stranded.
- (Matrix strand) (M1) b) hybridizing a primer oligonucleotide (P1 .1) to a segment comprising a portion of the target sequence (primer binding site) of the provided
- Nucleic acid chain (M1) wherein the primer oligonucleotide (P1 .1) comprises the following ranges:
- a first region substantially sequence-specific, capable of binding to a complementary segment (primer binding site) comprising a portion of the target sequence within a provided nucleic acid sequence (M1),
- a second region (overhang) connected to the 5 'end of the first region or connected via a linker, which second region can be bound by a controller oligonucleotide (C1 .1); c) extension of the primer oligonucleotide (P.1.1) by a template-dependent polymerase to give a primer extension product (primer extension product, P1 .1 -Ext) which has a synthesized region in addition to the primer oligonucleotide (P1.1) which is substantially complementary to the nucleic acid chain comprising a target sequence (M1), wherein the primer extension product (P1 .1 -Ext) and the nucleic acid chain (M1) form a double strand under reaction conditions;
- controller oligonucleotide (C1.1) binding of a controller oligonucleotide (C1.1) to the primer extension product (P1.1-Tex), wherein the controller oligonucleotide (C1.1) comprises the following ranges:
- controller oligonucleotide (C1 .1) does not serve as a template for a primer extension of the primer oligonucleotide (P1 .1) and the controller oligonucleotide (C1 .1) with its first, second and third regions to the primer extension product (P1 1 -Ext) with displacement of complementary segments of the nucleic acid chain (M1) can bind.
- a target sequence comprises a polymorphic locus comprising at least one nucleotide position comprising at least two characteristic sequence variants in a target sequence. In certain embodiments, a target sequence comprises a polymorphic locus comprising at least two nucleotide positions comprising at least two characteristic sequence variants in a target sequence.
- a target sequence comprises a polymorphic locus comprising a length between one nucleotide to 100 nucleotides, such locus comprising at least two characteristic sequence variants of a target sequence.
- step (1) at least two template strands are provided, each template strand comprising a variant of a target sequence having a specific and characteristic sequence variant of a polymorphic locus.
- each template strand comprising its own target sequence and these
- Target sequences of the first and another start nucleic acid chain are different.
- Polymerase remains essentially unkopiert under the selected reaction conditions.
- steps (b) to (d) are repeated at least once.
- the target sequence of the nucleic acid chain (M1) comprises a length of 20 nucleotides to 200 nucleotides.
- primer oligonucleotide (P1 .1) has a length in the range of 15 nucleotides to 100 nucleotides.
- controller oligonucleotide (C1 .1) has a length in the range of 20 nucleotides to 100 nucleotides.
- reaction conditions include a reaction temperature in the range of 25 ° C to 80 ° C.
- the primer oligonucleotide (P1 .1) in the second region has a modification or several modifications, in particular immediately after the first region of the primer oligonucleotide (P1 .1), which prevents the polymerase used from copying the second area.
- kit for carrying out a method according to one of the preceding numbers
- a primer oligonucleotide comprising the following ranges:
- a first region that can bind substantially sequence-specifically to a complementary segment (primer binding site) within a provided nucleic acid sequence (M1) comprising a target sequence,
- a second region (overhang) connected to the 5 'end of the first region or connected via a linker, which second region can be bound by a controller oligonucleotide (C1 .1);
- first primer oligonucleotide (P1 .1) when hybridized to the complementary segment of the target sequence, is replaced by a template-dependent polymerase can be extended to a primer extension product (P1 1-Ext) comprising a synthesized region in addition to the primer oligonucleotide (P1 .1);
- controller oligonucleotide (C1 .1) comprising the following ranges:
- controller oligonucleotide (C1 .1) is not used as a template for a
- Primer extension of the primer oligonucleotide (P1 .1), and the controller oligonucleotide (C1 .1) with its first, second and third region to the primer extension product (P1 1 -Ext) with displacement of complementary segments of the nucleic acid chain (M1 ) can bind; and optional
- a block oligonucleotide (B1 .1) that can bind to a segment of the nucleic acid chain (M1) that is in the 5 ' direction from the segment (primer binding site) that is located in the first region of the primer oligonucleotide (P1 .1) wherein the block oligonucleotide (B1 .1) is adapted to block the synthesis of the primer extension product (P1 1 -Ext) at the bound region and thereby to limit the length of the synthesized region of the primer extension product.
- Kit according to No. 15, characterized in that the second region of the primer oligonucleotide (P1 .1) remains substantially uncoated by a polymerase used for the primer extension under the chosen reaction conditions.
- a method for the specific extension of a primer oligonucleotide comprising the steps:
- nucleic acid chains comprising variants of a target sequence (template strand) (M 1 .1 and M 1 .2), wherein provided
- a first region substantially sequence-specific, capable of binding to a complementary segment (primer binding site) comprising a portion of the target sequence within a unitary segment of nucleic acid chains provided (M 1 .1 and M 1 .2), a second region (overhang) which connects to the 5 'end of the first region or is linked via a linker, which second region can be bound by a controller oligonucleotide (C 1 .1 or C 1 .2);
- a third region which is complementary to at least part of the synthesized region of at least one expected first primer extension product (P1 .1 -Ext or P1 2-Ext); and wherein the controller oligonucleotides (C1 .1 and C1 .2) do not serve as template for primer extension of the primer oligonucleotide (P1 .1), and the controller oligonucleotide (C1 .1) with its first, second and third regions to the complementary segments of the primer extension product (P1 1 -Ext) with displacement of the
- Nucleic acid chain (M 1 .1) can bind and
- controller oligonucleotide (C1 .2) with its first, second and third region to the complementary segments of the primer Extension product (P1 2-Ext) with displacement of
- Nucleic acid chain (M 1 .2) can bind.
- extension of the primer oligonucleotide (P.1.1) by a template-dependent polymerase using provided nucleic acid chains as templates for primer extension to give specific primer extension products (primer extension products, P1 .1-Ext and P1 2 Each) in addition to the primer oligonucleotide (P1 .1) comprises a synthesized region which is substantially complementary to the respective nucleic acid chain comprising a target sequence (M1), wherein
- the primer extension product (P1 1 -Ext) comprises a synthesized complementary region to the characteristic and specific segment of the one nucleic acid (M 1 .1) and
- the primer extension product (P1 2-Ext) comprises a synthesized complementary region to the characteristic and specific segment of the second nucleic acid (M 1 .2) and
- step (e) binding of at least one controller oligonucleotide (C1 .1 and C 1 .2) to the primer extension products (P1 1-Ext and P1 2-Ext) formed in step (e), wherein
- the controller oligonucleotide (C1 .1) with its first, second and third region can bind to the complementary segments of the primer extension product (P1 1 -Ext) with displacement of the nucleic acid chain (M 1 .1) and
- the controller oligonucleotide (C1 .2) with its first, second and third region to the complementary segments of the primer extension product (P1 2-Ext) with displacement of the nucleic acid chain (M 1 .2) can bind.
- nucleic acid chains comprising variants of a target sequence (template strand) (M 1 .1 and M 1 .2) comprise at least two uniform segments, which is identical in M1 .1 and M1 .2.
- the unitary segment comprises a length of 10 to 180 nucleotides.
- a method for the specific extension of a primer oligonucleotide comprising the steps:
- nucleic acid chains comprising variants of a target sequence (template strand) (M 1 .1 and M 1 .2), wherein provided nucleic acid chains
- Nucleic acid chains can bind complementary, wherein each primer oligonucleotide
- a first region each of which can sequence-specifically bind to a complementary segment (primer binding site) comprising a portion of the target sequence within a characteristic and specific segment of nucleic acid chains provided (M 1 .1 and M 1 .2),
- a second region connected to the 5 'end of the first region or connected via a linker, which second region can be bound by a controller oligonucleotide (C 1 .1 or C 1 .2);
- a first region which can bind to the second region of the primer oligonucleotides (P1 .1 and / or P1 .2) (overhang), and a second region which can be bound to the first region of the respective primer oligonucleotide (P1 .1 or P1 .2) is complementary, where
- corresponding first area of P1 .1 comprises and C 1 .2 a complementary second area to
- controller oligonucleotides (C 1 .1 and C 1 .2) do not serve as template for a primer extension of a primer oligonucleotide used (P 1 .1 or P 1 .2),
- the primer extension product (P1 .1 -Ext) comprises a complementary region to the characteristic and specific segment of the one nucleic acid (M 1 .1) and
- the primer extension product (P1 2-Ext) comprises a complementary region to the characteristic and specific segment of the second nucleic acid (M 1 .2) and
- step (e) binding of at least one controller oligonucleotide (C1 .1 and C 1 .2) to the primer extension products (P1 1-Ext and P1 2-Ext) formed in step (e), wherein
- controller oligonucleotide (C1 .1) with its first, second and third region to the complementary segments of the primer Extension product (P1 1 -ext) displacing the
- Nucleic acid chain (M 1 .1) can bind and
- the controller oligonucleotide (C1 .2) with its first, second and third region to the complementary segments of the primer extension product (P1 2-Ext) with displacement of the nucleic acid chain (M 1 .2) can bind.
- a method of specifically extending a primer oligonucleotide using a competitor primer comprising the steps of:
- nucleic acid chains comprising variants of a target sequence (template strand) (M 1 .1 and M 1 .2), wherein provided
- a first region capable of binding sequence-specifically to a complementary segment (primer binding site) comprising a portion of the target sequence within a characteristic and specific segment of nucleic acid chains provided (M 1 .1), a second region (overhang) attached to the 5 'end of the first region is connected or connected via a linker, wherein the second region of a controller oligonucleotide (C 1 .1) can be bound;
- the competitor primer oligonucleotide comprises a first region which is sequence-specific, to a complementary segment (primer binding site) comprising a portion of the target sequence within a characteristic and specific segment of the nucleic acid chain provided ( M 1 .2), where
- this region is not identical to the first region of the first primer oligonucleotide
- controller oligonucleotide (C1 .1), wherein the controller oligonucleotide comprises the following ranges:
- controller oligonucleotide (C 1 .1) does not serve as a template for a primer extension of a used first primer oligonucleotide (P 1 .1) or a competitor primer oligonucleotide,
- the primer extension product (P1 .1 -Ext) comprises a complementary region to the characteristic and specific segment of the one nucleic acid (M 1 .1) and
- the primer extension product (P5.2-Ext) comprises a complementary region to the characteristic and specific segment of the second nucleic acid (M 1 .2) and
- the synthesized primer extension products (P1 .1-Ext and P5.2-Ext) and their corresponding template nucleic acid chain (M 1 .1 and M 1 .2) form a double strand under reaction conditions;
- controller oligonucleotide (C1 .1) with its first, second and third region to the complementary segments of the primer extension product (P1 1 -Ext) with displacement of
- Nucleic acid chain (M 1 .1) can bind, wherein
- controller oligonucleotide (C1 .1) is unable to bind to the P5.2-Ext under used reaction conditions and to separate P5.2-Ext from its template strand.
- a first primer oligonucleotide and a corresponding controller oligonucleotide are combined to form a primer extension system.
- a primer extension system comprises:
- a specific controller oligonucleotide for a sequence variant of the target sequence is a specific controller oligonucleotide for a sequence variant of the target sequence
- a first primer oligonucleotide which can bind to the sequence fragment which is the same for the target sequence (template strand) which is provided in a substantially complementary manner, and
- the first primer oligonucleotide does not comprise sequence segments which are specific for a sequence variant of the target sequence. Rather, the first one Primer oligonucleotide fully complementary or intrinsically complementary to the target sequence bind, without distinguishing the sequence variants.
- Such a primer extension system is thus constructed such that the polymorphic locus of the target sequence is located in the sequence segment which lies in the 3 ' primer extension direction of the first primer.
- the segment of the controller oligonucleotide corresponding to the polymorphic locus thus lies in its third region.
- a first primer oligonucleotide and a corresponding controller oligonucleotide are combined to form a primer extension system.
- a primer extension system comprises:
- a first sequence variant-specific primer oligonucleotide which can bind at least partially (for example with its 3 ' terminal nucleotide) to the specific sequence segment of a polymorphic locus of a target sequence provided fully complementary.
- such a primer extension system is thus constructed such that the sequence of the first primer oligonucleotide overlays at least one nucleotide position with a characteristic sequence of the polymorphic locus.
- the segment of the controller oligonucleotide corresponding to the polymorphic locus is, in certain embodiments, completely in the second region of the controller oligonucleotide.
- the segment of the controller oligonucleotide corresponding to the polymorphic locus lies partially in the second and partially in the third region of the controller oligonucleotide.
- a first primer oligonucleotide and a corresponding controller oligonucleotide and a competitor primer oligonucleotide are combined to form a primer extension system.
- a primer extension system comprises:
- a specific controller oligonucleotide for a sequence variant of the target sequence is a specific controller oligonucleotide for a sequence variant of the target sequence
- a first primer oligonucleotide which can bind to the sequence fragment which is the same for the target sequence (template strand) which is provided in a substantially complementary manner, and
- a specific competitor primer oligonucleotide is A specific competitor primer oligonucleotide.
- the first primer oligonucleotide does not comprise any sequence segments which are specific for a sequence variant of the target sequence. Rather, the first primer oligonucleotide completely complementary or intrinsically complementary to the target sequence, without distinguishing the sequence variants.
- Such a primer extension system is thus constructed such that the polymorphic locus of the target sequence is located in the sequence segment which lies in the 3 ' primer extension direction of the first primer.
- the segment of the controller oligonucleotide corresponding to the polymorphic locus thus lies in the third region of the controller oligonucleotide.
- the competitor oligonucleotide used may bind fully or partially to the segment of the target sequence which may bind complementary to the first region of the first primer oligonucleotide.
- this competitor primer oligonucleotide is fully complementary to a sequence variant of a target sequence which is not identical to the sequence variant of the template strand recognized by the first primer.
- a competitor primer oligonucleotide does not comprise a sequence segment which is capable of substantially complementary binding to the first region of the controller oligonucleotide.
- a first primer oligonucleotide and a corresponding controller oligonucleotide and a competitor oligonucleotide are combined to form a primer extension system.
- a primer extension system comprises:
- a first sequence variant-specific primer oligonucleotide which can bind at least partially (for example with its 3 ' terminal nucleotide) to the specific sequence segment of a polymorphic locus of a target sequence provided fully complementary
- such a primer extension system is thus constructed such that the sequence of the first primer oligonucleotide overlays at least one nucleotide position of a characteristic sequence of the polymorphic locus.
- the segment of the controller oligonucleotide corresponding to the polymorphic locus is, in certain embodiments, completely in the second region of the controller oligonucleotide.
- the segment of the controller oligonucleotide corresponding to the polymorphic locus lies partially in the second and partially in the third region of the controller oligonucleotide.
- the competitor oligonucleotide used may bind fully or partially to the segment of the target sequence which may be complementary to the first region of the first primer oligonucleotide. In certain embodiments, this competitor primer oligonucleotide is fully complementary to a sequence variant of a target sequence which is not identical to the sequence variant of the template strand recognized by the first primer.
- a competitor primer oligonucleotide does not comprise a sequence segment which is capable of substantially complementary binding to the first region of the controller oligonucleotide.
- the application describes the preparation of primer extension products which can be used, for example, in an exponential amplification as starting nucleic acid.
- the first primer oligonucleotides and controller oligonucleotides used herein may be identical to or different from those of exponential amplification.
- the technical problems mentioned in the introduction are achieved, in particular, by the provision of methods and components (feedback system) which can check the quality of synthesized primer extension products in different phases of a template-dependent primer extension.
- this check can take place either during the synthesis or only after completion of the synthesis.
- the check can take place in the same reaction batch, so that the actual primer extension reaction does not have to be interrupted (online control) or only after completion of the primer extension reaction (final control).
- these components form a feedback system for the primer extension reaction or for the release of the product of the primer extension reaction from the template.
- the components of the feedback system can exert an influence on the primer extension reaction in such a way that it is possible to decide between a continuation of the enzymatic synthesis or an interruption of the synthesis or restart of the synthesis. Furthermore, the components of the feedback system can exert influence that the detachment of the product of the synthesis from the template is continued depending on the compliance with the controller oligonucleotide or is stopped or delayed or completely interrupted in the event of any deviations occurring in the sequence ,
- the synthesis system in a primer extension reaction typically comprises at least one template and at least one primer capable of binding more or less specifically to the template and initiating a primer extension reaction. Furthermore, the synthesis system comprises at least one polymerase, as well as substrates (dNTPs) and Buffer conditions under which a primer extension reaction can take place. Other oligonucleotides may be added depending on the embodiment of the method, eg block oligonucleotides, for sequence-specific stop of the polymerase or probe oligonucleotides which can deliver a fluorescence signal.
- the feedback system comprises a primer which acts as an initiator of a primer extension reaction and another oligonucleotide, a so-called controller oligonucleotide.
- the primer of the feedback system is identical in a preferred embodiment with the primer of the synthesis system.
- the controller oligonucleotide is capable of interacting with both the particular primer and the primer extension product sequence-specific from that primer. It is capable of forming a complementary duplex under reaction conditions upon sequence alignment with the primer extension product.
- the controller oligonucleotide itself does not serve as a template for synthesis for the said primer / polymerase system.
- Other oligonucleotides may be added depending on the embodiment of the method, e.g. Block oligonucleotides for sequence-specific stop of the polymerase or probe oligonucleotides which can deliver a fluorescence signal.
- the method comprises a primer extension reaction (also called primer extension) by means of a primer in the presence of a suitable controller oligonucleotide in the same reaction mixture.
- the controller oligonucleotide is capable of interacting with the primer extension product to form a complementary strand.
- the progress of the formation of the double strand between the controller and the primer extension product (P1 -Ext) depends essentially on the correspondence of the sequences between the controller and the corresponding primer extension product. As a result, a sequence check or sequence check can already take place during a primer extension or immediately after a primer extension at least over partial segments of the synthesized primer extension fragment by means of controller oligonucleotides.
- the method includes a template-dependent primer extension method in combination with subsequent control of the synthesized primer extension product by at least one controller oligonucleotide upon completion of the primer extension reaction.
- Primer extension and controller interaction with the synthesized primer extension product are two temporally separate reactions.
- the primer extension reaction proceeds in the same reaction mixture in the presence of a corresponding controller oligonucleotide, the reactions are temporally separated by the choice of reaction conditions in individual reaction steps.
- the presence of the feedback system in the same reaction as the primer extension reaction makes it possible to design a homogeneous assay.
- the components of the feedback system into the same reaction approach as the primer extension reaction per se, ie simultaneous presence of both the components of the synthesis system and the feedback system, checking or influencing the primer extension reaction and the separation of the primer extension products of if necessary, the matrix can be made in very short time intervals. This allows the feedback system to respond very quickly to any deviations that may occur.
- the simultaneous presence of the feedback system in the primer extension approach can lead to a repeated review, so that the result of the review can be summarized as the sum of multiple verification events.
- the frequency of the verification can be determined both by the appropriate choice of reaction conditions (eg temperature, concentration of the feedback system components) and by the structures of feedback components (eg length and complementarity or extent of the use of modified nucleotides in the design of individual structures). to be influenced.
- the feedback system should allow for correct-running reactions (in many cases more than 99% of primer extension strands of a primer extension reaction due to a high natural specificity of an enzymatic template-dependent reaction) and falsely synthesized primer extension products (less than 1% of all primer extension products ).
- a feedback system can be helpful, for example, in trace analysis.
- High sequence-dependent interaction of the primer extension product (P1-Ext) with the controller can be used to individually influence equilibria between individual intermediate complexes generated during the reaction. Since these complexes have different accessibility to certain sequence segments (single-stranded segments), many reactions can be affected during a running primer extension reaction. Possible intermediate complexes include e.g.
- Primer extension product / probe thus, one can exert greater influence on the specificity in the overall process of primer extension as well as in dependent reactions.
- the primer extension can take place as a single synthesis in one step or as a repeated reaction (linear amplification).
- the primer extension reaction may be performed alone or in combination with an amplification method.
- Sequence checking by the method according to the invention takes place beyond the primer length (about 5 to 50 nucleotides of the synthesized section) and thus differs from conventional primer extension reactions, in which essentially the primer sequence is responsible for the sequence-specific binding.
- the improved specificity of the deletion of the synthesized strand can be advantageously used in several aspects in detection methods.
- it may be used as an alternative detection method and / or component for genetic alterations such as single nucleotide polymorphisms.
- the sequence-specifically synthesized strand of the primer extension product is the desired product of the primer extension reaction. It can be used in various methods of analyzing genetic information, for example in: o generating one or more copies from a longer nucleic acid chain, e.g. a genomic DNA or its segments, or an RNA or its equivalents such as cDNA or segments thereof. These copies can be used as starting nucleic acid chains in amplification methods, such as PCR or other amplification methods; or.
- nucleic acid fragment e.g. an amplification fragment
- the components and methods should, especially in the simultaneous presence of several, very similar variants of a template sequence, eg wild-type and one or more mutated sequences, support an improvement in the specificity of individual process steps.
- the advantages of the method are particularly evident in the simultaneous presence of several, very similar variants of a template sequence, eg wild-type and one or more mutated sequences.
- components for a homogeneous assay are to be provided which allow a simultaneous presence of components in a reaction (one-pot reaction or homogeneous assay).
- primer extension reaction described here and the thereby generated primer extension products can serve as starting nucleic acids in an amplification process, for example.
- such amplification occurs as an exponential amplification in which newly synthesized products of both primers (primer extension products) occur as templates for further synthetic steps.
- This primer sequences are at least partially copied, so that complementary primer binding sites arise, which are present immediately after their synthesis as sequence segments of a double strand.
- synthesis steps of both strands and double-stranded opening steps of the newly synthesized sequence segments are made in mutual alternation. Adequate duplex separation after synthesis is an important prerequisite for further synthesis. Overall, such a variety of synthetic and double-stranded separation steps can lead to exponential amplification.
- controller oligonucleotide In the amplification process, the double-stranded opening of the main products of the amplification (amplification of nucleic acid chains comprising target sequence) takes place inter alia by means of an oligonucleotide, termed controller oligonucleotide.
- the controller oligonucleotide comprises sequence segments corresponding to the target sequence.
- strand separation is achieved by use of the controller oligonucleotide with predefined sequences which preferentially separate a newly synthesized double strand consisting of both specific primer extension products by means of a sequence-dependent nucleic acid-mediated strand displacement.
- the resulting single-stranded segments of primer extension products comprise the target sequence, as well as corresponding primer binding sites, which can serve as binding sites for further primer oligonucleotides, such that exponential amplification of amplicons to be amplified
- Nucleic acid chains is achieved.
- the primer extension reactions and Strand displacement reactions preferably take place simultaneously in the batch.
- the amplification is preferably carried out under reaction conditions which do not permit spontaneous separation of both specific synthesized primer extension products.
- a specific exponential amplification of a nucleic acid sequence comprising a target sequence comprises a repetition of synthesis steps and double strand opening steps (activation steps for primer binding sites) as a mandatory prerequisite for the amplification of the nucleic acid chain.
- the opening of synthesized duplexes is implemented as a reaction step which is to be sequence-specifically influenced by the controller oligonucleotide. This opening can be complete, even to dissociation of both complementary primer extension products, or even partial.
- the controller oligonucleotide comprises sequence segments which can interact with the target sequence and further sequence segments which bring about this interaction or facilitate or favor it.
- double-stranded sections of the synthesized primer extension products are converted into single-stranded form via sequence-specific strand displacement. This process is sequence dependent: only when the sequence of the synthesized duplex has some degree of complementarity with the corresponding sequence of the controller oligonucleotide will there be sufficient double-stranded opening such that the sequence portions essential to the continuation of the synthesis, e.g. Primer binding sites are converted into single-stranded form, which corresponds to an "active state".
- the controller oligonucleotide thus "specifically" activates the newly synthesized primer extension products comprising the target sequence for further synthetic steps.
- sequence segments which do not comprise a target sequence are not converted to the single-stranded state and remain as a double strand, which corresponds to an "inactive" state.
- the potential primer binding sites in such a duplex are less favored or completely hindered in interaction with new primers, so that further synthetic steps on such "non-activated" strands generally do not occur.
- This lack of or decreased activation (ie conversion to a single-stranded state) of synthesized nucleic acid strands after a synthesis step results in the fact that in the subsequent synthesis step only a reduced amount of primers can successfully participate in a primer extension reaction.
- the reaction conditions eg temperature
- the controller oligonucleotide facilitates this double-stranded separation as a result of matching its sequence segments with predetermined sequence segments Primer extension products.
- Predominantly sequence-specific separation of the double strand with the assistance of a controller oligonucleotide can be combined in combination with sequence-specific or less sequence-specific primers.
- the invention is particularly useful in primer extension reactions of sequence variants of a known locus of a target sequence.
- a locus can comprise several occurring sequence variants of a target sequence and is thus a polymorphic locus (FIGS. 12-15).
- a polymorphic locus includes, for example, single nucleotide polymorphisms.
- a sequence variant of a locus of the target sequence components which play an essential role in the specificity of primer extension should be placed in a specific arrangement.
- Particularly advantageous arrangements are those which comprise a known sequence variant of a locus, wherein a predominantly sequence-specific controller oligonucleotide and corresponding primers can be designed.
- the position of an expected sequence variant in the known locus is thus taken into account in the design of components such that at least the controller oligonucleotide, better controller oligonucleotide in combination with at least one primer, has a specific sequence composition in a primer extension system is suitable for primer extension of a desired variant of the target sequence.
- a primer extension system comprises at least one sequence-specific primer (eg allele-discriminating primer) in combination with one specific controller oligonucleotide (eg allele-specific controller oligonucleotide).
- a specific combination of at least one specific primer and at least one specific controller oligonucleotide may be provided. This results in a specific amplification of one of the possible sequence variants of a target sequence.
- a primer extension system comprises at least two, in particular four sequence-specific primers (eg allel-discriminating primers) in combination with in each case one specific controller oligonucleotide (eg allele-specific controller oligonucleotide). includes.
- sequence-specific primers eg allel-discriminating primers
- controller oligonucleotide eg allele-specific controller oligonucleotide.
- a primer extension system at least one sequence-specific primer (eg allele-discriminating primer) in combination with a specific controller oligonucleotide (eg allele-specific controller oligonucleotide) and at least one further primer (a competitor primer) which has a complementary sequence composition to other expected sequence variants.
- a specific combination of at least one specific primer and at least one specific controller oligonucleotide may be provided. This results in a specific primer extension of one of the possible sequence variants of a target sequence.
- the object of the invention is further solved by analyzing both strands of a double-stranded nucleic acid chain, wherein in one reaction the components of a primer extension system are provided for a strand of a target nucleic acid, which is used as starting nucleic acid, and in a separate Approach is provided to components for the complementary strand of the target nucleic acid chain which is used as the starting nucleic acid.
- a primer extension system in one reaction the components of a primer extension system are provided for a strand of a target nucleic acid, which is used as starting nucleic acid
- a separate Approach is provided to components for the complementary strand of the target nucleic acid chain which is used as the starting nucleic acid.
- a primer extension system comprises at least one primer which can support a primer extension of several potential sequence variants (eg a target sequence specific primer, but not an allelic discriminating primer, but a target sequence specific one allele -unspecific primer) in combination with each specific controller oligonucleotide (eg, allele-specific controller oligonucleotide).
- a specific combination of at least one allele-unspecific primer and at least one Allele-specific controller oligonucleotide can be provided for each specific composition of a target sequence and its specific variants (eg, alleles). This results in a specific primer extension of one of the possible sequence variants of a target sequence.
- the oligonucleotides required for a primer extension are summarized as a target sequence-specific primer extension system.
- a parallel primer extension of more than one target sequence is to be made possible by using multiple target sequence-specific primer extension systems in a reaction approach, wherein preferably target sequence-specific components are combined in each case.
- controller oligonucleotide thus allows a sequence-dependent review of the contents of the primer extension products after single synthesis steps or during primer extension and to bring about a selection of sequences for subsequent synthesis steps.
- active single-stranded states of newly synthesized specific primer extension products may result as a result of successful interaction with a controller oligonucleotide
- active double-stranded states of newly synthesized non-specific primer extension products as a result of deficient and / or insufficient and / or decreased and / or slowed interaction with a controller oligonucleotide.
- oligonucleotide as used herein with reference to primer, controller oligonucleotide, probes and the nucleic acid chain to be amplified is defined as a molecule comprising two or more, more preferably more than three deoxyribonucleotides and / or ribonucleotides and / or nucleotide Modifications and / or non-nucleotide modifications.
- its length encompasses ranges between 3 to 300 nucleotide units (where natural bases and analogues can be used together or alone), in particular between 5 to 200 nucleotide units.
- One skilled in the art will be able to determine the exact size depending on the ultimate function or use of the oligonucleotides.
- primer refers to an oligonucleotide, whether naturally occurring e.g. B. occurs in a purified restriction cleavage or was produced synthetically.
- a primer is capable of acting as the initiation point of the synthesis when used under conditions which induce the synthesis of a primer extension product complementary to a nucleic acid strand, i. H. in the presence of nucleotides and an inducing agent, e.g. DNA polymerase at a suitable temperature and pH.
- the primer is preferably single-stranded for maximum efficiency in primer extension.
- the primer must be long enough to initiate synthesis of the extension product in the presence of the inducing agent.
- the exact length of the primer will depend on many factors, including reaction temperature and primer source and application of the method. For example, the length of the oligonucleotide primer in diagnostic applications, depending on the complexity of the target sequence between 5 to 100 nucleotides, in particular 6 to 40 and especially 7 to 30 nucleotides. Short primer molecules generally require lower reaction temperatures to perform their primer function to form sufficiently stable complexes with the template, or higher concentrations of other reaction components, such as DNA polymerases, such that sufficient elongation of formed primer is achieved. Template complexes can be made.
- the primers used herein are selected to be "substantially" complementary to the different strands of each specific sequence to be amplified. That is, the primers must be sufficiently complementary to hybridize with their respective strands and initiate a primer extension reaction. Thus, for example, the primer sequence does not need to reflect the exact sequence of the target sequence.
- a non-complementary nucleotide fragment may be attached to the 5 'end of the primer, with the remainder of the primer sequence being complementary to the strand.
- single non-complementary bases or longer non-complementary sequences may be inserted into a primer, provided that the primer sequence has a sufficiently large complementarity with the strand sequence to be amplified to hybridize therewith and thus form a primer template. Complex able to produce the synthesis of the extension product.
- a primer extension product is generated, which is completely complementary to the template strand.
- sequences refers to hybridizing sequences with reverse complementary base sequence.
- Allele-specific primers are primers which are capable of their sequence composition, preferably under stringent reaction conditions on each individual sequence variants a target sequence to be hybridized and extended by a polymerase using the target sequence.
- Single allele-specific primers can be grouped together to cover all variants of a common target sequence.
- Such a group of allele-specific primers comprises at least two different allele-specific primers, as a polymorphic locus at a given position in the target sequence comprises at least two sequence variants.
- the allele-specific primers are selected to bind under stringent reaction conditions, preferably with their respective perfect-match template, and thus use this specific perfect-match template to form the respective primer extension products under the catalytic action of the polymerase.
- 3 ' -terminal segments of allele-specific primers can be used to discriminate variants of target sequences and are thus adapted in their sequence composition to the respective variants such that such primers form a perfect match double strand under stringent conditions with the respective variant.
- Such perfect-match double strands can usually be recognized well by a polymerase and under suitable reaction conditions a primer extension occurs.
- the interaction of an allele-specific primer with another variant of a target sequence thus results in a mismatch double strand.
- mismatches usually lead to a delay in the extension by a polymerase or to a slowing of the overall reaction.
- allele-specific primers in the 3 ' segment may include at least one phosphorothioate linkage that protects allele-specific primers from 3 ' -5 ' nuclease degradation by a polymerase.
- multiple allele-specific primers include sequence segments which are substantially identical for a group of allele-specific primers, as well as sequence segments which are different among the primers of a group and characteristic of the respective sequence variant of a target sequence.
- Including uniform sequence segments such primers can hybridize to the respective target sequence under reaction conditions.
- Including characteristic sequence segments a respective primer can specifically bind to a sequence variant of the target sequence to form a perfect-match double strand.
- the primers are designed so that, under used reaction conditions, binding to a target sequence to form a perfect match double strand is preferred and binding to a target sequence to form a mismatch duplex is less preferred.
- the first primer oligonucleotide is provided as an allele-specific primer in combination with a corresponding allele-specific controller oligonucleotide.
- the second primer oligonucleotide is provided as an allele-specific primer in combination with a corresponding allele-specific controller oligonucleotide.
- the melting temperature of a complementary or partially complementary double strand is generally understood to mean a measured value of a reaction temperature at which approximately half of the strands are in the form of a double strand and the other half is in the form of a single strand.
- the system association and dissociation of strands is in equilibrium.
- the Tm of a nucleic acid to be amplified should be determined under the same conditions, like the intended primer extension reaction.
- melting temperature is understood to mean a value which was measured in the same reaction buffer as the exponential amplification, at concentrations of both complementary components of a double strand of about 0.1 pmol / l to about 10 pmol / in particular in a concentration of about 0.3 pmol / to about 3 pmol / l, in particular about 1 pmol / l.
- the respective value of the melting temperature is a guideline, which correlates with the stability of a respective double strand.
- a melting temperature for a double strand can be roughly estimated.
- Several commercial suppliers allow a theoretical calculation of an expected melting temperature.
- OligoAnalyzer 3.1 available online from IDT (Integrated DNA Technologies) can be used to estimate the strength of the bonds of individual oligonucleotides.
- dNTPs deoxyribonucleoside triphosphates
- dATP deoxyribonucleoside triphosphates
- dCTP deoxyribonucleoside triphosphates
- dGTP deoxyribonucleoside triphosphates
- TTP dUTP, or dUTP / TTP mixture
- these dNTP analogs include, in certain embodiments, a characteristic label (eg, biotin or fluorescent dye) such that when incorporated into nucleic acid strand, this label is also integrated into the nucleic acid strand.
- this at least one modification of the sugar-phosphate moiety of the nucleotide for example, alpha-phosphorothioate 2
- alpha-phosphorothioate 2 include dNTP analogues '-Desoxyribonukleosid triphosphates (or other modifications which impart a nucleic acid strand a nuclease resistance), 2', 3 'dideoxy-ribonucleoside triphosphates, Azyklo nucleoside triphosphates (or other leading to the termination of a synthetic modifications).
- these dNTP analogs include at least one modification of nucleobase, eg, iso-cytosines, iso-guanosines (or other modifications of extended-genetic alphabet nucleobases), 2-amino-adenosines, 2-thiouridines, inosines, 7-deazy aadenosines, 7-deaza-guanosines, 5-Me-cytosines, 5- Propyl uridines, 5-propyl cytosines (or other modifications of nucleobases that can be incorporated into natural nucleobases by a polymerase and result in alteration of strand stability).
- nucleobase eg, iso-cytosines, iso-guanosines (or other modifications of extended-genetic alphabet nucleobases), 2-amino-adenosines, 2-thiouridines, inosines, 7-deazy aadenosines, 7-deaza-guanosines, 5-Me-cytosines, 5-
- a dNTP analog comprises both a modification of the nucleobase and a modification of the sugar-phosphate moiety.
- at least one other type of dNTP analogue is added to the synthesis mixture instead of at least one natural dNTP substrate.
- the nucleic acid synthesis-inducing agent may be an enzyme or a system that functions to cause synthesis of the primer extension products.
- Suitable enzymes for this purpose include e.g. template-dependent DNA polymerases such as Bst polymerase and its modifications, Vent polymerase and others - particularly heat-stable DNA polymerases that allow the incorporation of the nucleotides in the correct manner, thereby forming the primer extension products that are complementary to each nucleic acid strand synthesized.
- the synthesis is initiated at the 3 'end of each primer and proceeds along the template strand until the synthesis is complete or interrupted.
- polymerases which are capable of strand displacement. These include, for example, the large fragment of Bst polymerase or its modifications (e.g., Bst 2.0 DNA polymerase), Klenow fragment, Vent exo minus polymerase, Deepvent exo minus DNA polymerase, large fragment of Bsu DNA polymerase, large fragment of Bsm DNA polymerase.
- polymerases which have no 5 ' -3 ' -Exonuklease activity, or have no 5 ' -3 ' -FFEN activity.
- At least two different polymerases are used, for example, polymerases capable of strand displacement and those having 3 ' -5 ' reproducing activity.
- polymerases are used with a hot-start function, which can only perform their function when a certain temperature is reached.
- the primer oligonucleotide comprises a first primer region and a second region.
- the first primer region is capable of binding to a substantially complementary sequence within the nucleic acid or its equivalents to be amplified and initiating a primer extension reaction.
- the second region comprises a polynucleotide tail which is capable of binding a controller oligonucleotide and thereby effecting spatial proximity between the controller oligonucleotide and the other portions of the first primer extension product sufficient to induce strand displacement through the controller oligonucleotide.
- the second region of the first primer oligonucleotide further comprises at least one modification (a nucleotide modification or a non-nucleotide modification) which prevents the polymerase from copying the polynucleotide tail by inhibiting the continuation of the polymerase-dependent synthesis.
- This modification is located, for example, at the junction between the first and the second region of the primer oligonucleotide.
- the first primer region of the primer oligonucleotide is thus replicable by a polymerase so that a complementary sequence to this region can be generated during synthesis of the second primer extension product from the polymerase.
- the polynucleotide tail of the second region of the primer oligonucleotide is preferably not copied by the polymerase.
- this is achieved by the modification in the second region, which stops the polymerase from the polynucleotide tail. In certain embodiments, this is achieved by nucleotide modifications in the second region, where the entire polynucleotide tail consists essentially of such nucleotide modifications and thus is uncopatible to the polymerase.
- each primer oligonucleotide is specific for each nucleic acid to be amplified.
- each primer oligonucleotide is specific for at least two of the nucleic acids to be amplified, each comprising substantially different sequences.
- the primer oligonucleotide is labeled with a characteristic marker, e.g. a fluorescent dye (e.g., TAMRA, fluorescein, Cy3, Cy5) or an affinity tag (e.g., biotin, digoxigenin) or an additional sequence fragment, e.g. for binding a specific oligonucleotide probe for detection or immobilization or barcode labeling.
- a characteristic marker e.g. a fluorescent dye (e.g., TAMRA, fluorescein, Cy3, Cy5) or an affinity tag (e.g., biotin, digoxigenin) or an additional sequence fragment, e.g. for binding a specific oligonucleotide probe for detection or immobilization or barcode labeling.
- At least a first primer oligonucleotide is provided as an allele-specific primer in combination with at least one corresponding allele-specific controller oligonucleotide.
- a primer extension product results from enzymatic (polymerase-dependent) extension of a primer oligonucleotide as a result of template-dependent synthesis catalyzed by a polymerase.
- a primer extension product comprises the sequence of the primer oligonucleotide in its 5 ' segment and the sequence of the extension product (also called extension product) which has been synthesized by a polymerase in a template-dependent form. That by the Polymerase synthesized extension product is complementary to the template strand on which it was synthesized.
- a specific primer extension product (major product) comprises sequences of the nucleic acid chain to be amplified. It is the result of a specific synthesis or a correct execution of an intended primer extension reaction in which the nucleic acid chain to be specifically amplified serves as a template.
- the length of the extension product of a specific primer extension may be between 10 and 300 nucleotides, in particular between 10 and 180 nucleotides, in particular between 20 and 120 nucleotides, in particular between 30 and 80 nucleotides.
- a nonspecific primer extension product includes sequences that have arisen as a result of a nonspecific or improper primer extension reaction. These include, for example, primer extension products that have resulted as a result of a false initiation event (false priming) or as a result of other side reactions, including polymerase-dependent sequence changes such as base substitution, deletion, etc.
- the level of sequence aberrations of nonspecific primer extension products generally exceeds the ability of controller oligonucleotides to successfully displace such double-stranded by-products from their templates so that amplification of such by-products is slower or completely absent.
- the extent of acceptance or the tolerance limit for deviations depend, for example, on the reaction temperature and the manner of the sequence deviation.
- examples of nonspecific primer extension products are primer dimers or sequence variants which do not correspond to the nucleic acid to be amplified, e.g. Sequences which do not comprise a target sequence.
- the assessment of a sufficient specificity of the amplification is often related to the task. In many amplification methods, some degree of unspecificity of the amplification reaction can be tolerated as long as the desired result can be achieved.
- the proportion of nucleic acid chains to be amplified in the overall result of the reaction is more than 1%, in particular more than 10%, in particular more than 30%, based on the total amount of newly synthesized strands.
- the sequence of the synthesized primer extension products is completely consistent with the expected sequence of a nucleic acid to be amplified. In another embodiment, deviations in the sequence obtained may be tolerated by the theoretically expected sequence. In certain embodiments, the degree of agreement of the sequence obtained is due to a Amplification with the sequence of the theoretically expected nucleic acid to be amplified, for example, between 90% and 100%, in particular, the agreement is greater than 95%, in particular, the agreement is greater than 98% (measured on the proportion of synthesized bases).
- the first primer extension product is formed from a first primer oligonucleotide.
- a competitor primer extension product is formed starting from a competitor primer oligonucleotide ( Figures 21-23).
- a primer extension product in certain embodiments, may serve as a start-up nucleic acid chain comprising a target nucleic acid-comprising sequence.
- a target sequence is a segment of a nucleic acid chain to be amplified which can serve as a characteristic sequence of the nucleic acid to be amplified. This target sequence can serve as a marker for the presence or absence of another nucleic acid.
- This other nucleic acid thus serves as the source of the target sequence and can be for example a genomic DNA or RNA or parts of the genomic DNA or RNA (eg mRNA), or equivalents of the genomic DNA or RNA of an organism (eg cDNA, modified RNA such as rRNA, tRNA, microRNA, etc.), or defined changes in the genomic DNA or RNA of an organism, for example mutations (eg deletions, insertions, substitutions, additions, sequence amplification, eg repeat propagation in the context of microsatellite instability), splice variants, rearrangement variants (eg, T-Ze II receptor variants), etc.
- mutations eg deletions, insertions, substitutions, additions, sequence amplification, eg repeat propagation in the context of microsatellite instability
- splice variants eg, rearrangement variants (eg, T-Ze II receptor variants), etc.
- the individual target sequences may represent a phenotypic trait, such as antibiotic resistance or prognostic information, and thus be of interest for diagnostic assays / assays.
- a source / origin of a target sequence such a nucleic acid may comprise, for example, the target sequence as a sequence element of its strand.
- a target sequence can thus serve as a characteristic marker for a particular sequence content of another nucleic acid.
- the target sequence can be single-stranded or double-stranded. It may be substantially identical to the nucleic acid to be amplified or may be only part of the nucleic acid to be amplified.
- Equivalents of the target sequence include nucleic acids with substantially identical information content.
- complementary strands of a target sequence have identical informational content and can be said to be equivalent;
- RNA and DNA variants of a sequence are also examples of equivalent informational content.
- such a target sequence can be isolated from its original sequence environment and prepared for the amplification reaction.
- Particular embodiments of the target sequence are particularly preferred:
- a nucleic acid to be amplified comprises a target sequence.
- the target sequence corresponds to the nucleic acid to be amplified.
- a start-up nucleic acid chain comprises a target sequence.
- the target sequence corresponds to a starting nucleic acid chain.
- the nucleic acid to be amplified represents a nucleic acid chain which is to be amplified sequence-specifically or at least predominantly sequence-specifically by means of the exponential amplification using primers and controller oligonucleotide by the polymerase.
- the length of the nucleic acid to be amplified may be between 20 and 300 nucleotides, in particular between 30 and 200 nucleotides, in particular between 40 and 150 nucleotides, in particular between 50 and 100 nucleotides.
- the nucleic acid sequence to be amplified may comprise one or more target sequences or their equivalents.
- a nucleic acid to be amplified may comprise sequences substantially complementary to a target sequence which are propagated with similar efficiency as a target sequence in an amplification reaction and comprise the target sequence or its portions.
- the nucleic acid to be amplified may include additional sequence segments, for example, primer sequences, sequences with primer binding sites and / or sequence segments for binding of detection probes, and / or sequence segments for sequence encoding of strands by barcode sequences and / or sequence segments for binding to a solid phase.
- the primer sequences or their sequence portions, as well as primer binding sites or their sequence portions may for example belong to sequence sections of a target sequence.
- the nucleic acid to be amplified corresponds to the target sequence.
- the target sequence forms part of the sequence of the nucleic acid chain to be amplified.
- a target sequence may be flanked by 3 ' side and / or 5 ' side of further sequences.
- These further sequences may include, for example, binding sites for primers or their moieties, and / or comprising primer sequences or their moieties, and / or binding sites for detection probes, and / or adapter sequences for complementary binding to a solid phase (eg, Im Frame of microarrays, or bead-based analyzes) and / or include barcoding sequences for a digital signature of sequences.
- a nucleic acid chain In order for the amplification to start, a nucleic acid chain must be added to the reaction mixture at the beginning of the reaction, which occurs as an initial template for the synthesis of the nucleic acid chain to be amplified. This nucleic acid chain is called the start nucleic acid chain.
- This start nucleic acid chain gives the arrangement of individual Sequence elements which are important for the formation / synthesis / exponential amplification of a nucleic acid chain to be amplified.
- the initial template which is initially added to an amplification reaction, or which is added to the reaction mixture, corresponds to the sequence composition of the nucleic acid sequence to be amplified.
- the respective primers In initial stages of the amplification reaction, and in its progression, the respective primers bind to the corresponding binding sites in the starting nucleic acid chain and initiate the synthesis of specific primer extension products.
- specific primer extension products accumulate exponentially in the course of amplification and increasingly assume the role of templates for the synthesis of complementary primer extension products in exponential amplification.
- the nucleic acid chain to be amplified is thus formed.
- the major product of the reaction (the nucleic acid to be amplified) may be predominantly single-stranded or predominantly a complementary duplex. This can be determined, for example, by the relative concentration of both primers and corresponding reaction conditions.
- nucleic acid to be amplified include nucleic acids having substantially identical information content.
- complementary strands of a nucleic acid to be amplified have identical information content and can be said to be equivalent.
- a target sequence may comprise several naturally occurring sequence variants or artificially introduced sequence changes. Such variants are often called polymorphisms of a locus or allele sequences. Furthermore, these variants of a target sequence can map specific changes in the natural state of the DNA, which arise, for example, by mutations / mutagenesis and represent characteristic features of such a clonal propagation process (eg in cancer diseases or in biotechnologically exploitable strains).
- Single allele sequences of a target sequence may be sequence differences comprising single nucleotides (eg A-> G or T-> C substitutions or single nucleotide insertions or deletions) or a sequence difference may also comprise several nucleotides (eg 2 up to 200 nucleotides). These may, for example, be deletions / insertions / transversions / duplications etc.
- a sequence segment comprising such sequence variants of a target sequence is often called a polymorphic locus.
- a target sequence may include one or more polymorphic loci.
- sequence positions of single allelic variants of a target sequence are generally known and thus allow for design of sequence-specific reaction components, eg, controller oligonucleotides or combinations comprising a controller oligonucleotide and a first primer or a controller oligonucleotide and a second primer.
- sequence-specific reaction components eg, controller oligonucleotides or combinations comprising a controller oligonucleotide and a first primer or a controller oligonucleotide and a second primer.
- a target sequence which may include multiple sequence variants in a polymorphic locus, further comprises at least a first target sequence segment that is characteristic and unique to all target sequence variants of a target sequence (target sequence group).
- a target sequence comprises at least two target sequence segments (a first target sequence segment and a second target sequence segment, each target sequence segment is characteristic and uniform to all target sequence variants of a target sequence (target sequence group).)
- Such uniform target sequence segments are preferably located and flanked on both sides of a polymorphic locus thus, a polymorphic locus (with sequence variants) of a target sequence from both sides
- the first unitary target sequence segment in its sequence composition is different from the sequence composition of the second unitary target sequence segment in at least one nucleotide position.
- the length of a polymorphic locus of a target sequence may comprise regions of one nucleotide up to 200 nucleotides, in particular from one nucleotide up to 100 nucleotides, in particular from one nucleotide up to 50 nucleotides, in particular from one nucleotide up to 20 nucleotides.
- the lengths of a unitary sequence segment may comprise at least for one of the two segments: from 6 to 300 nucleotides, in particular from 10 to 200 nucleotides, in particular from 15 to 100 nucleotides, in particular from 20 to 100 nucleotides ,
- individual sequence variants of a target sequence group may be grouped together, such variants being defined for at least one unitary and specific sequence segment for that target sequence (target sequence group). Individual sequence variants of such a target sequence (target sequence group) thus differ by sequence segments of the polymorphic locus.
- individual sequence variants of a target sequence group may be grouped together, such variants being defined for at least two unitary and specific sequence segments for that target sequence (target sequence group).
- Individual sequence variants of such a target sequence (target sequence group) thus differ by sequence segments of the polymorphic locus.
- the polymorphic locus is between both unitary sequence segments.
- two different target sequences can each be specifically amplified in an amplification reaction.
- Different target sequences are characterized in that they are preferably differentiable among each other by sequences specific and characteristic of each target sequence.
- different target sequences are differentiable in their entire length by specific and characteristic sequences and thus do not comprise any sequence segments which are identical for both target sequences.
- different target sequences may comprise at least one sequence segment that is substantially similar or even identical for at least two different target sequences.
- the length of such a sequence segment is equal to or less than 19 nucleotides (counted as coupled nucleotide positions), more preferably equal to or less than 14 nucleotides (as mutually coupled nucleotide positions), more preferably equal to or less than 9 nucleotides (as mutually coupled nucleotide positions), in particular equal to or less than 5 nucleotides (as mutually coupled nucleotide positions).
- the start-up nucleic acid chain is a preferred embodiment of a sequence segment comprising target nucleic acid which is said to result as a product of a primer extension reaction.
- a nucleic acid chain In order for the amplification to start, a nucleic acid chain must be added to the reaction mixture at the beginning of the reaction, which occurs as an initial template for the synthesis of the nucleic acid chain to be amplified. This nucleic acid chain is called the start nucleic acid chain. This start nucleic acid chain predetermines the arrangement of individual sequence elements which are important for the formation / synthesis / exponential amplification of a nucleic acid chain to be amplified.
- Such a starting nucleic acid chain can be present in single-stranded or double-stranded form at the beginning of the reaction.
- the complementary strands of the starting nucleic acid chain are separated, regardless of whether the nucleic acid was originally double- or single-stranded, the strands can serve as a template for the synthesis of specific complementary primer extension products.
- the starting nucleic acid chain in certain embodiments, comprises a target sequence or its partial segments which comprise at least one expected sequence variant of a polymorphic locus of the target sequence.
- a start nucleic acid further comprises at least one predominantly single-stranded sequence segment to which at least one of the primers of the amplification system can bind predominantly complementary to its 3 ' segment, so that the polymerase used such a primer, when hybridized to the starting nucleic acid chain, may extend template-specific incorporation of dNTPs.
- a starting nucleic acid sequence in certain embodiments comprises a target sequence or its partial segments comprising at least one expected sequence variant of a polymorphic locus of the target sequence and at least one uniform sequence segment of a target sequence.
- a starting nucleic acid sequence in certain embodiments comprises a target sequence or its partial segments comprising at least one expected sequence variant of a polymorphic locus of the target sequence and at least two unitary sequence segments of a target sequence, wherein uniform sequence segments of a target sequence comprise the polymorphic locus with possible sequence variants Flank both sides.
- Controller oligonucleotide / Controller
- the controller oligonucleotide is a single-stranded nucleic acid chain that includes a predefined, substantially complementary sequence in a portion of the primer extension product that is specifically generated as part of the amplification of the nucleic acid to be amplified. This allows the controller oligonucleotide to bind substantially complementary to the primer oligonucleotide and at least to the 5 ' segment of the specific extension product of the primer oligonucleotide.
- the controller oligonucleotide in its interior sequence segment comprises nucleotide modifications that prevent the polymerase from synthesizing a complementary strand using the controller oligonucleotide as a template when the primer oligonucleotide is complementarily bound to the controller oligonucleotide.
- identical controllers are used in the primer extension reaction as in the subsequent acid reaction.
- the primer extension reaction uses a controller that differs from that in the subsequent acid reaction.
- the target sequence-specific controller oligonucleotide is preferably constructed such that it is capable of participating in amplification of preferably a defined specific sequence variant of a predefined target sequence.
- the allele-specific controller oligonucleotide is preferably constructed such that it is capable of preferentially effecting the amplification of a specific sequence variant of a target sequence (eg, allele 1), with another sequence variant of the same target sequence (eg, allele 2) the amplification proceeds with reduced efficiency or does not take place in the given time, or results in a yield of amplification products which is insufficient for a detection.
- a target sequence eg, allele 1
- a target sequence eg, allele 2
- the amplification proceeds with reduced efficiency or does not take place in the given time, or results in a yield of amplification products which is insufficient for a detection.
- there are measurable differences in the course of an amplification reaction which depend on whether the sequence of an allele variant specific controller oligonucleotide with the sequence of a provided at the beginning of the reaction nucleic acid chain, which serves as a start nucleic acid and the target sequence a polymorphic locus, specifically coincident
- An allele-specific controller oligonucleotide is thus not only provided target-specific, but also allele-specific. Thus, depending on the complexity of a polymorphic locus of a target sequence, multiple controller oligonucleotides specific for respective allelic variants of a target sequence can be constructed.
- a controller oligonucleotide comprises at least one sequence segment having a sequence composition complementary to a specific allelic variant of a target sequence. Furthermore, a controller oligonucleotide preferably comprises at least one sequence segment which comprises a complementary sequence which is identical for all sequence variants of a target sequence. In certain embodiments, a controller oligonucleotide comprises at least one sequence segment capable of complementarily binding to a variant of a polymorphic locus of a target sequence.
- multiple controller oligonucleotides are provided, each comprising allele-specific sequence segments.
- the length of a sequence segment of a controller oligonucleotide complementary to the polymorphic locus of a starting nucleic acid nucleus can comprise regions of one nucleotide up to 100 nucleotides, in particular from one nucleotide up to 50 nucleotides, in particular from one nucleotide up to 20 nucleotides.
- the length of at least one sequence segment of a controller oligonucleotide which is complementary to uniform sequence segments of a target sequence may comprise the following ranges: from 4 to 100 nucleotides, in particular from 6 to 100 nucleotides, in particular from 8 to 50 nucleotides.
- a sequence segment of a controller oligonucleotide that is complementary to at least one variant of a polymorphic locus of a target sequence is located in the third region of the controller oligonucleotide.
- a sequence segment of a controller oligonucleotide that is complementary to at least one variant of a polymorphic locus of a target sequence is located in the second region of the controller oligonucleotide.
- a sequence segment of a controller oligonucleotide that is complementary to at least one variant of a polymorphic locus of a target sequence becomes is partially and / or completely localized in the second and third regions of the controller oligonucleotide.
- base pairs under two nucleic acid strands can be carried out essentially complementary, which means that between 70% and 100%, in particular between 90% and 100%, in particular between 95% and 100% of nucleotides of a strand can complement each other in a complementary manner.
- a nucleotide position in a strand of 20 nucleotides may not have a complementary bond, which corresponds to 95% complementarity.
- the formation of complementary base pairings is preferably 100% between both strands of a duplex.
- a perfect-match duplex thus does not include a mismatch between the strands.
- controller oligonucleotide / primer system feedback system
- primer-template system synthesis system
- the controller oligonucleotides preferably do not serve as templates for primer extension.
- the extension of corresponding primers to controller oligonucleotides is preferably prevented by a modification of controller strands.
- the controller oligonucleotide is capable of binding to an overhang on the primer (the first region of the controller oligonucleotide preferably specifically binds to the second region of the corresponding primer) and is capable of complementary binding with the primer (the second region of the controller Oligonucleotide binds to the first region of the primer). Furthermore, the controller can bind with its third region to the synthesized portion of the primer extension product predominantly sequence-specific.
- the primers used have a tail or overhang which can not form a stable duplex with the template (the primer overhang remains completely or partially free upon primer binding to the primer binding site of the template) and thus interacts with the first Area of the controller oligonucleotide is available.
- This primer overhang serves as a binding site for each specific controller oligonucleotide strand (first region of the controller oligonucleotide). The controller oligonucleotide binds to this overhang and is thus brought into spatial proximity with the duplex.
- the controller oligonucleotide can undergo double-stranded invasion to form a complementary double strand (this process is also referred to as branch migration or sequence-dependent strand displacement).
- Strand invasion occurs to form a new double strand between a controller oligonucleotide and the corresponding strand of synthesized amplification fragments. Due to a strong sequence dependence of such a double strand formation, the opening of the synthesized double strands is highly dependent on the sequence match with the respective controller sequence.
- the primers have a tail or overhang which is not copied by a polymerase. The polymerase is prevented from copying the overhang by appropriate primer modifications.
- a primer extension system comprises at least one target sequence-specific controller oligonucleotide and at least one first primer oligonucleotide and at least one template-dependent polymerase capable of using a template comprising at least one characteristic target sequence or target sequence variant, Under suitable reaction conditions, to support a predominantly specific amplification of the nucleic acid chain to be amplified, whereby predominantly target sequence-specific first primer extension products are synthesized.
- An allele-specific primer extension system comprises at least one allele-specific controller oligonucleotide and at least one first primer oligonucleotide (where primers may be target sequence specific and / or allelic specific), as well as at least one template-dependent polymerase which is in is able, using a template which comprises at least one target sequence variant, under suitable reaction conditions, to support a predominantly specific amplification of the target sequence variant (one allele) of the nucleic acid chain to be amplified, wherein predominantly specific first primer extension products are synthesized.
- a primer extension system may comprise multiple allele-specific primer extension products, wherein each allele-specific primer extension system preferably copies at least one of the target sequence variants.
- a suitable agent leads to a complete or partial separation of a first double strand (consisting for example of A1 and B1 strand) and for the simultaneous / parallel formation of a new second double strand, wherein at least one of the strands ( A1 or B1) are involved in the formation of this new second strand.
- the formation of a new second duplex may be accomplished using an already existing complementary strand which is generally in single-stranded form at the beginning of the reaction.
- the means of strand displacement for example, a preformed single-stranded strand C1, which has a complementary sequence to the strand A1 acts on the first already formed double strand (A1 and B1) and goes with the strand A1 a complementary Binding, whereby the strand B1 is displaced from the bond with the strand A1.
- the displacement of B1 is complete, the result of the C1 action is a new duplex (A1: C1) and a single-stranded strand B1.
- the displacement of B1 is incomplete, the result depends on several factors. For example, a complex of partially double-stranded A1: B1 and A1: C1 may be present as an intermediate.
- the formation of a new second duplex may occur under concurrent enzymatic synthesis of the complementary strand, with one strand of the first preformed duplex appearing as a template for synthesis by the polymerase.
- the means of strand displacement acts on the first already preformed double strand (A1 and B1) and synthesizes a new strand D1 complementary strand D1, wherein at the same time the strand B1 from the bond with the strand A1 is displaced.
- nucleic acid mediated strand displacement is meant a sum / series of intermediate steps which can be in equilibrium with one another and, as a result, the temporary or permanent opening of a first preformed duplex (consisting of complementary strands A1 and B1) and a new second one Duplex (consisting of complementary strands A1 and C1) lead, where A1 and C1 are complementary to each other.
- an essential structural prerequisite for the initiation of strand displacement is the creation of a spatial proximity between a duplex end (preformed first duplex of A1 and B1) and a single stranded strand (C1) which initiates strand displacement (where A1 and C1 can form a complementary strand).
- Such spatial proximity can preferably be achieved by means of a single-stranded overhang (in the literature examples are known with short overhangs, which binds the single-stranded strand (C1) temporarily or permanently complementary, and thus complementary segments of the Stranges C1 and A1 in sufficiently close, so that a successful strand displacement of the strand B1 can be initiated.
- the efficiency of initiation of nucleic acid-mediated strand displacement is generally greater the closer the complementary segments of strand A1 and C1 are positioned to each other.
- nucleic acid-mediated strand displacement Another essential structural prerequisite for the efficient continuation of nucleic acid-mediated strand displacement in internal segments is the high complementarity between strands (eg, between A1 and C1), which must form a new double strand.
- strands eg, between A1 and C1
- single nucleotide mutations in C1 can lead to disruption of strand displacement (described, for example, for branch migration).
- the present invention makes use of the ability of complementary nucleic acids to sequence-dependent nucleic acid-mediated strand displacement.
- the technical problem of this embodiment is the synthesis of a primer extension product and subsequent separation of the primer extension product from its template.
- the separation of the primer extension product takes place with the assistance of a controller oligonucleotide and is thus preferably sequence-specific.
- the synthesis of the primer extension product and the checking by means of a controller oligonucleotide preferably takes place in the same batch (homogeneous assay), the individual reactions are temporally separated.
- the synthesis of the P1-Ext (synthesis phase) takes place (FIG. 3) and then the double strand is opened by means of a controller (controlling phase) (FIG. 4).
- the two phases can be used for example by changing the reaction temperature of the reaction mixture in a desired sequence (in a homogeneous assay) or by sequential addition as a heterogeneous format.
- a primer extension catalyzing agent a polymrease
- suitable substrates require the use of a modified controller such that the first primer, when hybridized to the controller oligonucleotide, is not is extended by a polymerase.
- a preferred form is described with a homogeneous format in which at least one template strand, at least one controller oligonucleotide, at least one primer oligonucleotide, at least one polymerase and dNTPs are present as substrates in a suitable buffer system at the beginning of the reaction.
- the goal of the synthesis phase is to synthesize a specific primer extension product by means of a polymerase-mediated synthesis using a suitable template strand.
- a primer extension reaction comprises a preferably specific primer binding
- Binding site (sequence segment capable of being predominantly complementary to the first Area of the primer oligonucleotide), wherein the second area of the primer (primer overhang) preferably does not bind to the template strand, and thus is available for later interaction with the controller.
- the primer binding site can be completely single-stranded or partially single-stranded, so that at least a portion of the first region of the primer can bind sequence-specifically to the primer binding site via complementary base pairs (Watson-Crick rule).
- the polymerase can now extend the bound to the primer binding site primer oligonucleotides in a template-dependent synthesis of complementary Anküpfung nucleotides into the growing strand of the primer (3 'end-OH), thereby creating a template strand complementary to the primer extension product (P1 ext).
- the synthesis of the complementary strand usually takes place under suitable reaction conditions until the polymerase finds enough substrate in the batch and sufficient sequence segments in the template strand are available in suitable form for the polymerase as template.
- the polymerase may be one of the conditions of the sequence segments that the template strand is single-stranded (using polymerases without strand displacement properties) or even partially or even completely double-stranded (using polymerases with strand displacement properties).
- the synthesis is often carried out over the sufficient time, so that from more than 5%, in particular more than 50%, in particular more than 90% of the template strands a primer extension product can be synthesized.
- the primer extension product (P1-ext) is present in complex with the template strand in double-stranded form (P1-Ext / template strand complex).
- This double-stranded complex comprising P1 -ext and template strand is preferably stable under selected reaction conditions of the primer extension phase and can not spontaneously dissociate into its constituents, or this spontaneous dissociation occurs very slowly and can thereby be neglected.
- primer binding occurs under reaction conditions that allow thermodynamically stable binding of the first region of the primer oligonucleotide to the corresponding complementary position in the template.
- reaction conditions are for example at reaction temperatures which are well below the melting temperature (Tm) of such a complex (P1 / template strand).
- Tm melting temperature
- the Tm should have been measured under the same buffer conditions.
- the reaction temperatures may range from Tm minus 50 ° C to Tm minus 5 ° C.
- the complex comprising primer / controller oligonucleotide is also in double-stranded form under such reaction conditions.
- primer oligonucleotide and controller oligonucleotide both in the first primer region and in the second Primer region (overhang / primer tail) interact, the bond between the first primer and the controller is usually more stable than between the first primer region and the template.
- the primer should be in excess so that enough primer in single-stranded form remains in the reaction and can react with the primer binding site of the template strand so that a primer extension reaction can take place.
- the concentration of a controller oligonucleotide is about 1 pmol / l
- the concentration of the first primer can be about 1, 1 to 5 pmol / l.
- the primer saturates the controller.
- the controller oligonucleotide is thus preferably present in the complex comprising primer / controller oligonucleotide during the synthesis phase, thereby being in an inert form.
- the controller does not interfere with the synthesis process.
- the first and second regions of the controller oligonucleotide are occupied by the primer oligonucleotide (corresponding to the first and second regions thereof) through the formation of a complementary strand and thus are not responsible for interactions with formed primer extension products during the synthesis phase available.
- the primer binding takes place under reaction conditions which do not permit thermodynamically stable binding of the first region of the primer oligonucleotide to the corresponding complementary position in the template.
- reaction conditions which do not permit thermodynamically stable binding of the first region of the primer oligonucleotide to the corresponding complementary position in the template.
- binding events complexes are formed which comprise the first region of the primer and the corresponding primer binding positions of the template.
- dissociation events these complexes separate into individual components, so that no primer extension reaction can start by means of polymerase.
- Such conditions are present, for example, at reaction temperatures which are about the melting temperature (Tm) of such a complex (P1 / template strand).
- Tm melting temperature
- the reaction temperatures may be in the range of Tm -5 ° C to Tm + 5 ° C, in particular embodiments in the range of Tm -5 ° C to about Tm +15 ° C, in another particular embodiment in the range of Tm -5 ° C to Tm +30 ° C.
- extension of the primer by a polymerase can be done with sufficient complementarity of the 3 ' segment of the primer with the template.
- the reaction can be slower or significantly slower compared to reaction conditions where stable primer binding occurs.
- reaction temperatures above Tm + 30 ° C (P1 / template) the primer extension reaction is usually so inefficient that such conditions are rarely used in primer extension reactions.
- the structure of the first primers and the controller oligonucleotides, as well as the reaction conditions of the synthesis phase are chosen such that the double-stranded complex comprising primer / controller oligonucleotide is present predominantly in double-stranded form.
- the controller oligonucleotide may thereby be saturated and thus preferably excluded from interactions with formed primer extension products. Since primer oligonucleotide and controller oligonucleotide interact both in the first primer region and in the second primer region (overhang / primer tail), the bond between the primer and the controller is generally more stable than between the first primer Area and the matrix.
- the melting temperature (Tm) of the complex comprising primer / controller oligonucleotide is generally higher than that of the complexes comprising primer / template.
- thermostable polymerases such as Taq polymerase / Pfu polymerases and thermolabile (such as Klenow polymerase fragment or MMLV reverse transcriptase) or mesophilic polymerases (eg Bst polymerase) can be used.
- the polymerases may comprise both a 3 'exonuclease activity (proofreading polymerases) or not.
- DNA-dependent polymerases or RNA-dependent polymerases can be used.
- Both polymerase can be used with (e.g., Bst polymerase and its modification such as Bst Large fragment) or without strand displacement properties (such as Taq polymerase or Pfu polymerase or MMLV reverse transcriptase).
- Bst polymerase and its modification such as Bst Large fragment
- strand displacement properties such as Taq polymerase or Pfu polymerase or MMLV reverse transcriptase
- the template strand comprises a primer binding site such that under selected reaction conditions binding of the first region of the first primer can occur and polymerase mediated synthesis of the strand can occur.
- a template strand comprises a target sequence.
- This target sequence usually comprises the sequence segment of the template strand, which performs the template function for the synthesis of the complementary strand.
- the template strand and the primer oligonucleotide are adapted in their design to each other such that the second region of the primer oligonucleotide does not bind to the template strand complementarily, or at least do not form stable complementary binding, and thus potentially capable of joining with the first region of the controller oligonucleotide.
- both DNA and RNA can occur as template strands.
- the primer binding site of the template is preferably in a single-stranded form and allows for site-specific binding of the first region of the primer oligonucleotide to the template.
- the target sequence of the template strand comprises at least one segment of the primer binding site so that the 3 ' segment of the first primer can bind complementary to the target sequence.
- the segment of the template strand which serves as a template for the synthesis of the complementary strand by the polymerase may, in certain embodiments, be wholly or predominantly (more than 50%) single-stranded under reaction conditions. In another embodiment, this segment is predominant (greater than 50%) or fully double-stranded.
- the polymerases used in the synthesis must be selected accordingly: in the case of single-stranded matrices, polymerases without strand displacement can be used, e.g. Taq polymerase or Pfu polymerase.
- polymerases having strand-displacing properties e.g. Bst polymerase Large Fragment or Vent polymerase or Klenow fragment.
- Combinations of several polymerases may also be used, e.g. Taq polymerase and Vent polymerase or Taq polymerase and Bst polymerase, or Pfu polymerase and Bst polymerase.
- Taq polymerase and Vent polymerase or Taq polymerase and Bst polymerase
- Pfu polymerase and Bst polymerase e.g. Taq polymerase and Vent polymerase
- Taq polymerase and Bst polymerase e.g., Taq polymerase and Bst polymerase
- Pfu polymerase and Bst polymerase e.g., Pfu polymerase and Bst polymerase.
- their selection depends on the specifications of the manufacturer. Both naturally occurring polymerases and their partial components (e.g., Klenow fragment or Bst polymerase Large Fragment) or modifications, e.g. Bst-2.0 polymerase or AmpliTaq polymerase).
- the primer binding site may be for the primer in the 3 ' segment of the template.
- the primer oligonucleotide comprises a modification (called the first blocking moiety) which prevents the polymerase from copying the second primer region.
- the template in its 3 ' segment can go well beyond the primer binding site of the primer.
- the length of such an overhang can range from a few nucleotides to several kilobases.
- the structure of such a template strand causes the primer overhang, starting from the 3 ' end of the template, not to be copied by the polymerase. Therefore, in such an embodiment, the primer need not necessarily comprise a block group (called the first blocking unit) in the second region of the primer. The second region can thus directly transition into the first region and be linked to the 5 ' end of the first region via the 5 ' - 3 ' -phosphate link.
- the synthesis of the primer extension product via polymerase as a template-dependent synthesis.
- the length of the primer extension product is preferably limited by the availability of a sequence segment of the template which can be used by the polymerase for synthesis. This can be achieved, for example, by limiting the template strand in the 5 ' sequence segment, which is available as a template for the complementary synthesis. This limitation prevents the polymerase used from continuing to continue the synthesis beyond this obstacle.
- strand termination strand termination
- one or more modifications in the strand eg spacer or linker or abasic bound phosphate residues
- nucleotide modifications eg nucleobase modification as Iso-C and Iso-G, or the sugar-phosphate moieties such as 2 '-0-Me, 2' MOE, morpholino, PNA etc.
- the synthesis of the polymerase can be stopped or stopped by using additional oligonucleotides on predetermined sequence segments.
- the progress of the synthesis of the primer extension product is limited by using at least one so-called block oligonucleotide ( Figures 3,4, 6-8). Under the reaction conditions of the synthesis phase, such a block oligonucleotide may preferably remain predominantly sequence-specifically hybridized to the template strand via complementary binding.
- Such a block oligonucleotide when complementarily attached to the template strand, prevents the polymerase from reading the template strand in the sequence portion bound by that oligonucleotide and, correspondingly, beyond.
- different embodiments of block oligonucleotides can be used. The selection of the oligonucleotide structure, the polymerase and the reaction conditions are based on the fact that the progressive synthesis is prevented or blocked by polymerase.
- the length of the block oligonucleotide and the nature of the Sequence composition is directed to the fact that the block oligonucleotide must remain stably bound to its complementary position of a template strand under reaction conditions of the synthesis phase and preferably can not spontaneously dissociate from the template.
- Such oligonucleotide is usually brought in 3 ' direction from the first primer oligonucleotide in effective concentrations in contact with the template strand prior to the start of a synthesis phase of a primer extension reaction and incubated for sufficient time at appropriate reaction conditions so that it can be bound to its can bind complementary position in the strand.
- oligonucleotides with exonuclease-resistant modifications e.g.
- PTO Phosphorothioate
- 2 '-0-Me modifications which primarily in the 5' segment of the oligonucleotide are positioned lead
- oligonucleotides complementary to the template can prevent Taq polymerase from cloning this oligonucleotide via 5 ' - '. 3-exonuclease-dependent degradation to cleave or detach from the template.
- Such a nucleotide is usually capable of preventing a Taq polymerase from reading the template strand segment bound by the block oligonucleotide.
- Oligonucleotides having multiple double-strand stabilizing modifications typically results in the polymerase being unable to continue synthesis via the oligonucleotide binding site.
- LNA or PNA double-strand stabilizing modifications
- template-complementary oligonucleotides of about 15-50 nucleotides in length with about 7-30 LNA modifications can prevent Bst polymerase (large fragment) from detaching this oligonucleotide via polymerase-dependent strand displacement from the template.
- Bst polymerase large fragment
- block oligonucleotides are known.
- PNA modifications or LNA modifications have been used in clamp-PCR methods to block polymerase synthesis.
- the length of the P1-text generated during the template-dependent synthesis and the length of the matching controller oligonucleotide can be chosen differently.
- the length of the controller oligonucleotide and the length of the expected primer extension product are matched to one another such that the Controller oligonucleotide covers the complete synthesized by the polymerase area.
- a controller oligonucleotide can completely detach the P1 -ext from the template. In the 3 ' segment of the P1 -ex, no free nucleotides remain for interaction with the template during the controlling phase (see below).
- the length of the controller oligonucleotide and the length of the expected primer extension product are matched to one another such that the length of the synthesized region of the primer extension product extends beyond the length of the controller oligonucleotide.
- the 3 ' segment of the primer extension product thus comprises a sequence segment which is not checked by the controller oligonucleotide.
- This double-stranded segment can spontaneously dissociate under the reaction conditions of the controlling phase, for example due to a temperature-induced strand opening (eg at temperatures of about 50-80 ° C).
- the length of this 3 ' segment of the primer extension product may comprise, for example, sequence lengths which lie in the following ranges: from 1 to 10 nucleotides, from 10 to 20 nucleotides, from 30 to 40 nucleotides, from 40 to 50 nucleotides, from 50 to 70 nucleotides, from 70 to 100 nucleotides.
- the synthesized primer extension product is now to be detached from the template by means of controller oligonucleotide and thus made available for further steps.
- the aim of the controlling phase is to check the synthesized primer extension product for its agreement with the given sequence.
- the sequence dependency of the double strand formation from primer extension product and controller oligonucleotide serves to check the synthesis quality during the primer extension reaction.
- the primer extension product is completely or partially detached from the template sequence-dependently.
- a formation of a double strand comprising primer extension product / controller oligonucleotide takes place at the same time.
- the primer extension product / controller strand (P1-Ext / Controller) complex is a prerequisite for opening the double strand (template / primer extension fragment) after primer extension.
- Sequence control is in this embodiment only after the synthesis of the primer extension product in a separate reaction step (controlling phase).
- the controller oligonucleotide is to form a double strand with the now synthesized in the synthesis phase P1 -Ext.
- controller oligonucleotide is already in the reaction mixture at the beginning of the synthesis reaction. Due to an excess of the primer oligonucleotide, the controller oligonucleotide is present as a complex comprising primer / controller.
- the temperature of the reaction mixture can be increased so that the primer / controller complexes become thermodynamically unstable.
- the reaction temperature should, however, be chosen so that the fully double-stranded complexes of primer extension product and template strand do not spontaneously disintegrate.
- the controller oligonucleotides are released from complexes (primers / controllers) and are in equilibrium with the regeneration of these complexes (e.g., at temperatures around the Tm of the primer / controller complexes ⁇ 3 to 8 ° C).
- the controller oligonucleotides which are now freely available, can interact with complexes of primer extension products and template strands in the second primer region (primer overhang). The interaction starts from the primer overhang. This establishes spatial proximity between the controller strand and the end of the double-stranded region between primer extension product / template strand. As a result, the double-stranded formation can be transferred between the controller and the first primer region (sequence-dependent strand displacement). Given the sequence identity with the synthesized portion of the primer extension product, the double strand formation between the controller oligonucleotide and the primer extension product continues to expand.
- the progression of this interaction between the synthesized primer extension product and the controller oligonucleotide results in increasing release of the template strand from the complex with the primer extension product.
- dissociation of the template complex and primer extension product occurs.
- a new complex is thereby formed which comprises the primer extension product and the controller oligonucleotide.
- a 3 ' segment of the primer extension product remains in binding with the template strand even though the controller oligonucleotide has completely bound to the primer extension product.
- the dissociation of this complex depends on the reaction conditions chosen during the controlling phase (see below).
- the successful interaction of components in the interaction of the controller oligonucleotide with the synthesized primer extension product and the spontaneous dissociation of the complex from the 3 ' segment of the P1 -ext and the template can be used to detach the primer extension product (in the complex of P1- Ext and COntrolelr strand) from the matrix. Discriminating effect of the controller oligonucleotide:
- the template oligonucleotide can be completely or partially detached from the template strand by binding with the primer extension product (displacement by template). Such displacement may be accomplished completely in certain embodiments. This can be done, for example, if under the reaction conditions used in the controlling phase the stability of the complex from the second region of the primer and the first region of the controller oligonucleotide is not sufficiently high and this complex can spontaneously dissociate into its subcomponents. Thus, the template strand acts against the controller oligonucleotide.
- Variations in the sequence of a primer extension product may be due to several causes, for example, the presence of multiple template strands with the same or similar primer binding sites and sequence variants at one or more positions in the segment of the template strand, e.g. in the presence of a polymorphic locus in the target sequence segment.
- Another cause of deviations may be, for example, synthesis errors / incorporation errors introduced by polymerases.
- primer extension products In the event of sequence deviations in the primer extension products from the template by the sequence composition of the controller oligonucleotide, such primer extension products preferably remain in double-stranded complexes with the template during the controlling phase.
- double-stranded complexes comprising a template strand and a primer extension product (which could not be detached from the controller) can not be an active form for further analysis steps.
- differentiation can be made between primer extension products: primer extension products detached from the template represent an active form of primer extension products.
- Primer extension products in complex with their template are preferably an inactive form.
- the use of a primer extension product in further reactions may require that certain portions of the P1-Ext be in single-stranded form. This may be necessary, for example, for binding a primer or a probe.
- This embodiment can therefore be used, for example, to convert the sequences in the 3 ' segment of the P1-E 1 in a single-stranded state.
- the primer extension product is only detached from the template if the synthesis is carried out correctly or only if it matches the complementarity with the controller oligonucleotide. In the case of deviations in the sequence, the primer extension product remains in complex with the template and the sequences in the 3 ' segment of the P1-Ext can not be converted into the single-stranded state (under used conditions).
- controller oligonucleotide after a primer extension reaction (synthesis phase) can be used for several technical tasks.
- the availability of controller oligonucleotide in the approach allows both a low-contamination integration in other methods of molecular analysis as well as a combination with other methods, such as amplification or detection methods.
- Some embodiments are therefore to be presented in more detail.
- a fully complementary primer extension product attached to a controller can be partially or fully protected from nuclease exposure if the nature of the controller string has been selected appropriately.
- nuclease resistant modifications to certain sequence segments of the third region of the Contollers or continuously over the whole third area of the controller such as PTO or 2 '-0-alkyl modifications
- the remaining primer extension products bound to the template strand can be selectively enzymatically cleaved by the action of a nuclease (e.g., restriction endonuclease or exonuclease).
- a nuclease e.g., restriction endonuclease or exonuclease
- a controller may further comprise an affinity tag, eg, a biotin residue (for example, covalently coupled to the 3 ' end or 5 ' end).
- an affinity tag eg, a biotin residue (for example, covalently coupled to the 3 ' end or 5 ' end).
- a primer extension product attached to the controller can be isolated by using a solid phase coated, for example, with streptavidin.
- the embodiment is based on the sequence-specific detachment / separation of the primer extension product from its template strand in the simultaneous presence of several different primer extension products in the same reaction mixture.
- template strands :
- multiple template strands (at least two) with a substantially similar primer binding site are used, but differ in the sequence of the template segment sequence.
- the differences between template strands are preferably in the 3 ' direction from the 3 ' end of the primer.
- the differences may include, for example, single nucleotide variations (eg, SNVs: substitutions, deletions, insertions), or insertions, deletions, duplications, inversions of multi-nucleotide sequence segments (eg, 2 to 200 nucleotides).
- a template strand comprises a target sequence comprising at least one polymorphic locus and further comprising at least one sequence segment which is uniform for all sequence variants of a target sequence.
- the primer binding site may be, for example, in the unitary sequence segment.
- the polymorphic locus is thus in the 3 ' direction from the 3 ' primer end.
- a single primer oligonucleotide is used which is capable of predominantly complementary binding to uniform primer binding sites of all template strands present in the anneal and initiating initiation of a synthetic reaction by a polymerase.
- At least one controller oligonucleotide constructed in its third region is used so that it is capable of binding to only a certain variant of the sequence of a possible primer extension product complementarily in the synthesized region of the primer extension product. If multiple controller oligonucleotides are used, each controller oligonucleotide is constructed sequence-specifically to a particular variant of the sequence.
- primer binding (through the first region of the primer oligonucleotide) can occur substantially without discrimination of single template strands.
- the polymerase is able to initiate synthesis of such bound primers and synthesizes complementary strands on the basis of the respective template strand. This results in primer extension products which are substantially complementary to the respective template strand and thus each comprise complementary segments to individual sequence variants of the template strands. During synthesis, the polymerase can not distinguish between these sequence differences of the template strands.
- the controller oligonucleotide is in double-stranded form in the primer / controller complex during the synthesis phase and does not interfere with the synthesis process.
- release of the controller oligonucleotide from the double-stranded complex primer / controller e.g. by raising the temperature (at a temperature at which the primer / controller complexes are at least partially dissociated, but complexes comprising primer extension products / template strands are substantially stable).
- the controller oligonucleotide which is now at least partially in single-stranded form, can interact through its first region with the second region of the primer, thus initiating strand displacement.
- the progress of the formation of the double strand between the first primer extension product and the controller oligonucleotide depends on the correspondence of the sequences of the third region of the controller oligonucleotide and the synthesized portion of the respective primer extension products.
- the second area of the controller is fully complementary to the first area of the first primer.
- the synthesis products differ depending on the template strand used. These differences can range from differences in only one nucleobase to completely different sequence composition of the primer extension product. Due to these differences in primer extension products, the outcome of the controlling phase is different. Predominantly, primer extension products with a sufficient degree of complementarity with the third region of the controller are replaced by their template strand. Thus, a differentiation between synthesized primer extension products takes place in the controlling phase:
- the controller oligonucleotides preferably form double-stranded complexes with complementary primer extension products. In case of a sequence deviation, this double-stranded formation takes place only insufficiently.
- primer extension products with sequence differences to the controller strands remain predominantly attached to their template strands.
- the now completely or partially detached primer extension product can be used in further analyzes. For example, it can be isolated from the reaction mixture (in bound form to the controller oligonucleotide). Furthermore, it can be used as a binding partner for other oligonucleotides, eg probes. Furthermore, it may even occur as a template strand, for example, after binding of a new primer in the 3 ' segment of the primer extension product.
- the embodiment is based on the sequence-specific detachment / separation of the primer extension product from its template strand in the simultaneous presence of several different primer extension products in the same reaction mixture.
- multiple template strands are used with a primer binding site, with the primer binding site being different for individual templates.
- the differences between template strands are preferably in a position which preferentially interacts with the 3 ' segment of the primer (e.g., positions 0, -1, -2, -3, -4, -5).
- the differences may include, for example, single nucleotide variations (eg, SNVs: substitutions, deletions, insertions), or insertions, deletions, duplications, or inversions of sequence segments of several nucleotides (eg, 2 to 10 nucleotides).
- first primer oligonucleotides In the primer extension reaction, several first primer oligonucleotides (more than two) are used.
- the respective first primer oligonucleotides are constructed in their 3 ' segment of the first primer region such that each primer oligonucleotide used comprises a specific sequence complementary to a particular sequence variant of the candidate template strands (eg, allele-specific primers).
- Such first primers are capable of predominantly complementary binding to their specific primer binding sites of the respective template strands and to initiate initiation of a synthetic reaction by a polymerase.
- the first primer oligonucleotides may comprise uniform or different second regions (primer overhang, oligonucleotide tail).
- the composition of the respectively specific controller oligonucleotides in the respective first region is adapted so that a specific pairing of an allele-specific first primer and a corresponding controller is possible and each controller in such a pair comprises a specific base sequence in the first region of the controller and each first primer oligonucleotide in such a pair has a correspondingly complementary sequence in the second region.
- the primer oligonucleotides can interact with controller oligonucleotides predominantly specifically during the controlling phase.
- At least one other primer which is not a first primer oligonucleotide can be used.
- a primer will be competitor primer Called oligonucleotide. It is capable of complementarily binding at least one sequence variant of a polymorphic locus of a target sequence and thereby forming a perfect match duplex, this sequence variant preferably being a sequence which is at least at one point with the first primer oligonucleotide Mismatch can form.
- each competitor primer oligonucleotide used comprises a specific sequence complementary to a particular sequence variant of the candidate template strands (eg, allele-specific primers).
- Such competitor primers are able to predominantly complementarily bind to their specific primer binding sites of the respective template strands and to initiate initiation of a synthetic reaction by a polymerase.
- competitor primers are also allele-specific primers which can not interact with the first region of the specific controller oligonucleotide and thus can not initiate strand separation.
- Competitor primers are said to substantially compete for binding to the primer binding site of the template strand with the first primer oligonucleotide and to be extended upon complementary binding to its complementary variant template strand from a polymerase, thereby forming a competitor primer extension product arises.
- the choice of the sequence of a competitor primer oligonucleotide depends primarily on the requirement to specifically exclude a specific sequence variant of a polymorphic locus from interaction with the first primer oligonucleotide and thus the non-specific interaction between a specific first primer oligonucleotide and a to prevent or minimize in the sequence deviating primer binding site of another sequence variant.
- a competitor primer oligonucleotide preferably does not comprise a sequence segment moiety which can interact with the controller oligonucleotide specific for the first primer oligonucleotide.
- At least one controller oligonucleotide constructed in its second region such that it is capable of having only one particular variant of the sequence of a sequence variant-specific first primer oligonucleotide, and thus only one particular variant of the invention, is used Sequence of a possible first primer extension product to bind complementarily in the first region of the primer extension product. If multiple controllers are used, each controller oligonucleotide is constructed sequence-specifically for a particular variant of the sequence. Multiple controller oligonucleotides may be used, which further differ in that they have in their first region a specific sequence which is capable of binding predominantly to the specific first primer oligonucleotide.
- Both partners each have specific sequence sections for this pair in the first primer region and in the second primer region, as well as correspondingly in the first and in the second region of the controller oligonucleotide.
- primer binding (through the first region of the first primer oligonucleotide) can occur substantially / preferably, discriminating the individual sequence variants of template strands.
- suitable reaction conditions are preferably used (so-called stringent reaction conditions).
- the polymerase is able to start synthesis from such correctly complementarily bound primers and synthesizes complementary strands on the basis of the respective template strand. This results in primer extension products which are substantially complementary to the respective template strand.
- the polymerase can not distinguish between these differences in template strands.
- the controller oligonucleotide is in double-stranded form in the primer / controller complex during the synthesis phase and does not interfere with the synthesis process.
- a competitor-primer bond and extension are additionally carried out in the synthesis phase:
- the competitor-primer binding may take place substantially / preferably with discrimination of the individual sequence variants of template strands.
- suitable reaction conditions are preferably used (so-called stringent reaction conditions).
- the polymerase is able to start a synthesis of such correctly complementarily bound competitor primers and synthesizes each complementary strands based on the respective template strand. This results in competitor primer extension products which are substantially complementary to the respective template strand. During synthesis, the polymerase can not distinguish between these differences in template strands.
- the release of the controller oligonucleotide from the double-stranded complex primer / controller occurs, eg by increasing the temperature (at a temperature at which the primer / controller complexes are at least partially dissociated, but stable complexes comprising primers). Extension products / template strands are present).
- the controller oligonucleotide which is now at least partially in single-stranded form, can through its first region to interact with the second region of the primer and thus start the strand displacement.
- the progress of the formation of the double strand between the primer extension product and the controller depends on the correspondence of the sequences of the second region of the controller and the synthesized portion of the respective primer extension products.
- the synthesis products differ depending on the primers and template strands used. Due to these differences in the primer extension products, the result of the controlling phase is different. Predominantly, primer extension products with a sufficient degree of complementarity with the second region of the controller oligonucleotide are detached from their template strand. Thus, there is a discrimination between the synthesized primer extension products in the controlling phase:
- the controller oligonucleotides preferably form double-stranded complexes with complementary primer extension products. In case of a sequence deviation, this double strand formation takes place insufficiently.
- the primer extension products with sequence differences to controller strands remain predominantly attached to their template strands.
- the specifically formed competitor primer extension products can not be released from their template strands under the control of a controller since the competitor primers lack corresponding second regions (primer overhang) which could interact in a complementary manner with the first region of the controller.
- the completely or partially detached sequence-specific primer extension product can be used in further analyzes. For example, it can be isolated from the reaction mixture (in bound form on the controller oligonucleotide). Furthermore, it can be used as a binding partner for other oligonucleotides, eg probes. Furthermore, it can even occur as a template strand, for example, after binding of a new primer in the 3 ' segment of the primer extension product.
- the specific primer extension products synthesized in a primer extension reaction can be used as a starting nucleic acid in subsequent amplification procedures.
- a defective synthesis of primer extension products by polymerases represents a significant problem for the genetic analyzes.
- individual nucleotides are exchanged by the polymerase during the synthesis (eg instead of a correct one) C is installed a T or instead of an A, a G is installed, etc.).
- C is installed a T or instead of an A, a G is installed, etc.
- the present embodiment is intended to reduce synthesis errors in fully synthesized primer extension products in a primer extension reaction.
- the technical problem of this embodiment is solved by the synthesis of a primer extension product and the elimination of the incorrectly synthesized strands occurring in parallel to synthesis.
- the elimination of the incorrectly synthesized strands is accomplished by separating the primer extension product from its template before the primer extension product has reached its full length. This separation of the primer extension products takes place with the assistance of a controller oligonucleotide.
- the synthesis of the primer extension product and the checking by means of a controller oligonucleotide are carried out in the same way (homogeneous assay), the individual reactions being essentially parallel to one another. This results in an influence of the controller oligonucleotides on the synthesis during the synthesis process.
- the synthesis of the primer extension product (P1-Ext) during the synthesis phase and the opening of the double strand by means of a controller oligonucleotide (controlling phase) are adapted to one another in such a way that predominantly a processively occurring correct primer extension in a complete synthesis in resulting in a template strand complementary primer extension product.
- the defective primer extension products comprising at least one incorporation error introduced during synthesis by a polymerase are to be selected out.
- a preferred embodiment with a homogeneous format is described in which at least one template strand, at least one controller oligonucleotide, at least one primer oligonucleotide, at least one polymerase and dNTPs are present as substrates in a suitable buffer system at the beginning of the reaction. Synthesis phase.
- the goal of the synthesis phase is to synthesize a specific primer extension product by polymerase-mediated synthesis using a template strand.
- a primer extension reaction comprises a preferably specific primer binding (first region of the primer oligonucleotide) to the template strand at a suitable primer binding site (sequence segment capable of complementary binding to the first region of the primer oligonucleotide) the second region of the primer (primer overhang) preferably does not bind to the template strand and is therefore available for later interaction with the controller.
- the primer binding site can be completely single-stranded or partially single-stranded so that at least a portion of the first region of the primer can bind sequence-specifically to the primer binding site via formation of complementary base pairs (Watson-Crick rule).
- the polymerase can extend such bound to the primer binding site primer oligonucleotides in a template-dependent synthesis of complementary attachment nucleotides into the growing strand of the primer (3 'end-OH). This results in a complementary to the template strand primer extension product (P1-Ext).
- the synthesis of the complementary strand usually takes place as long as the polymerase finds enough substrate in the batch and sufficient sequence segments in the template strand are available in a suitable form for the polymerase as a template.
- one of the conditions on the template segment may be that the template strand is single-stranded (using polymerases without strand displacement properties) or else partially double-stranded (using polymerases having strand displacement properties).
- the synthesis reaction often takes place over a sufficient time (total time of the reaction), so that at more than 1%, in particular more than 10%, in particular more than 30%, in particular more than 50% of the template strands a complete primer extension product can be synthesized.
- primer binding occurs under reaction conditions which do not allow thermodynamically stable binding of the first region of the primer oligonucleotide to the corresponding complementary position in the template.
- reaction conditions which do not allow thermodynamically stable binding of the first region of the primer oligonucleotide to the corresponding complementary position in the template.
- binding events complexes are formed which comprise the first region of the primer and the corresponding primer binding positions on the template strand.
- dissociation events these complexes separate into individual components so that no primer extension reaction can start by means of polymerase.
- Such conditions are present, for example, at reaction temperatures which are about the melting temperature (Tm) of such a complex (P1 / template strand).
- the melting temperature (Tm) should be measured under the same buffer conditions and concentrations.
- the Reaction can be carried out under reaction temperatures in the range of Tm -5 ° C to Tm +30 ° C, in particular embodiments in the range of Tm -5 ° C to about Tm +20 ° C, in another particular embodiment in the range of Tm -5 ° C to Tm +10 ° C. Even under such conditions, extension of the primer by a polymerase can occur with sufficient complementarity of the 3 ' segment of the primer with the template.
- the structure of the primers and the controller oligonucleotides, as well as the reaction conditions of the synthesis phase are chosen such that the complex comprising primer / controller oligonucleotide is predominantly in equilibrium with its individual components (complex formation and complex dissociation occur parallel to each other) , Such conditions are for example at reaction temperatures, which are about the melting temperature (Tm) of such a complex (primer / controller oligonucleotide).
- Tm melting temperature
- reaction may be carried out at reaction temperatures in the range of Tm -5 ° C to Tm + 30 ° C, in particular embodiments between about Tm -5 ° C to about Tm + 20 ° C, in another particular embodiment between about Tm - 5 ° C to about Tm + 10 ° C, in certain embodiments between about Tm -5 ° C to about Tm + 5 ° C, in another particular embodiment between about Tm - 5 ° C to about Tm -2 ° C.
- Tm melting temperatures
- reaction conditions formation and dissociation of primer / primer-binding site complexes as well as formation and dissociation of primer / controller-oligonucleotide complexes occur.
- the structures and reaction conditions are adapted to each other in such a way that, under such conditions, extension of the primer by a polymerase can occur with sufficient complementarity of the 3 ' segment of the primer with the template.
- Combinations of structures of the individual components and the reaction conditions are advantageous, which even with a primer extension of only a few nucleotides lead to the fact that even an incompletely extended primer extension product can be more tightly bound to the controller oligonucleotide than a primer that is still extender. This is usually done by allowing the controller oligonucleotide to form a complementary bond with a primer extension product with its third region, thus having additional binding positions compared to a primer / controller complex. Such a more stable binding also allows incompletely extended primers to form complexes with controller oligonucleotides and, due to sufficient stability of these complexes, be removed from the reaction.
- controller oligonucleotide does not support matrix function (eg, by modification), incompletely extended, to the controller Oligonucleotide bound primer not completed. For this reason, preferably the entire third region of the controller oligonucleotide comprises such modifications.
- the continuation of the synthesis of such incompletely extended primer / controller complexes can only take place when they are released again from the complex with the controller oligonucleotide. Due to advantageous selected reaction conditions, however, this is done only to a very limited extent. Thus, incompletely extended primer extension products can be bound in complexes with controller oligonucleotides during the synthesis reaction.
- the controller oligonucleotide may interact during the ongoing primer extension reaction (in parallel with this reaction) with both primer oligonucleotides, partially extended primers, and fully extended primers. This interaction begins at the second region of the primer.
- predominantly sufficient processive polymerases are used, e.g. Bst-Large fragment, Phi29 polymerase or polymerases with improved processivity (e.g., phage polymerase is a result of a coupling of a thermostable polymerase with a protein that extends the binding of the polymerase to the DNA) or their modifications.
- phage polymerase is a result of a coupling of a thermostable polymerase with a protein that extends the binding of the polymerase to the DNA
- controller oligonucleotides are used in concentrations of about 0.1 mM to about 20 pM. This allows a sufficiently frequent interaction with primer extension products so that an impact on the quality of primer extension products is expected.
- lower processivity polymerases e.g., Taq polymerase, Vent polymerase, Pfu polymerase
- controller concentrations of about 5 nM to about 1 pM are preferably used here.
- Polymerases are predominantly able to attach several nucleotides (eg more than 15 nucleotides, better more than 30 nucleotides, preferably more than 50 nucleotides) to the growing end of the primer or primer in the case of only one binding event to a primer / template strand complex. Extension product to tie.
- low-affinity polymerases such as Taq polymerase and Klenow polymerase, or entirely distributive polymerases, which bind only a few nucleotides in a binding event (usually less than 8 to 15 nucleotides).
- a predominantly processive synthesis is thus associated with the synthesis within a binding event of the polymerase to the primer-template complex.
- the high processivity of the polymerase is favored by sufficient complementarity of the 3 ' end of the growing primer extension product.
- the synthesis is carried out at high speed and processively particularly advantageous when the 3 ' end of the strand to be elongated fulfills a structural requirement for complementarity given by the template (as a rule, this refers to a complementary, perfect-match situation in the case of nucleobases between the 3 ' end or 3 ' segment of the strand to be elongated and the corresponding template ).
- This slowdown in the rate of polymerase catalysis is known to one skilled in the art.
- the extent of such slowing or pausing in catalysis depends on both the polymerase and the reaction conditions (eg, concentration of dNTPs) as well as the nature of the mismatch.
- the continuation of the synthesis beyond such a mismatch usually requires a longer reaction time.
- mismatch position comprising, as a rule, one to two nucleotides
- the polymerase can overcome the template-dependent synthesis can as a rule be continued.
- the extent of overcoming depends on both the type of mismatch and polymerase.
- Polymerases may or may not both comprise a 3 ' exonuclease activity (proofreading polymerases, eg, phage polymerase) (Bst-Large Fragment). Depending on the type of template used, DNA-dependent polymerases or RNA-dependent polymerases can be used.
- the template strand comprises a primer binding site such that under selected reaction conditions binding of the first region of the primer occurs and polymerase mediated synthesis of the strand can occur.
- a template strand comprises a target sequence.
- This target sequence usually represents the sequence segment of the template strand, which performs the template function for the synthesis of the complementary strand.
- the template strand and the primer oligonucleotide are adapted in their design such that the second region of the primer oligonucleotide does not bind to the template strand, or at least does not form stable binding, and thus is potentially able to interfere with the first region of the controller. Oligonucleotide to interact. In general, both DNA and RNA can occur as template strands.
- the primer binding site of the template is preferably in a single-stranded form and allows for site-specific binding of the first region of the primer oligonucleotide to the template.
- the segment of the template strand which serves as a template for the synthesis of the complementary strand by the polymerase may, in certain embodiments, be wholly or predominantly (more than 50%) single-stranded under reaction conditions. In another embodiment, this segment is predominantly (more than 50%) double-stranded.
- the polymerases used in the synthesis must be selected accordingly. For single-stranded templates, polymerases can be used without marked strand displacement, e.g. Phusion polymerase. For predominantly double-stranded segments of the template, preference is given to using polymerases having strand-displacing properties, e.g. Bst polymerase Large Fragment.
- the primer binding site may be for the primer in the 3 ' segment of the template.
- the primer oligonucleotide comprises a modification which prevents the polymerase from copying the second primer region.
- the template in its 3 ' segment can go well beyond the primer binding site of the primer.
- the length of such an overhang can range from a few nucleotides to several kilobases.
- the structure of such a template strand results in the primer overhang not being copied by the polymerase starting from the 3 ' end of the template. Therefore, in such an embodiment, the primer need not necessarily comprise a block group in the second region of the primer.
- the synthesis of the primer extension product via polymerase as a template-dependent synthesis. It is advantageous if the progress of the synthesis of the primer extension product is limited and thus a desired primer extension product is limited in its length.
- the length of the complete primer extension product is preferably limited by availability of a sequence segment of the template which can be used by the polymerase for synthesis. This can be achieved, for example, by limiting the matrix strand in the 5 ' segment. This limitation prevents the polymerase used from continuing the synthesis.
- Such a limitation can be achieved, for example, by strand termination (strand termination achieved eg by physical action or by an enzyme, eg an endonuclease or a restriction endonuclease) or by using one or more modifications in the strand (eg spacer or linker) prevent the polymerase from being synthesized, or by nucleotide Modifications (eg nucleobase modification as Iso-C and Iso-G, or the sugar-phosphate moieties such as 2 '-0-Me, 2' MOE, morpholino, PNA etc.).
- nucleotide Modifications eg nucleobase modification as Iso-C and Iso-G, or the sugar-phosphate moieties such as 2 '-0-Me, 2' MOE, morpholino, PNA etc.
- a so-called block oligonucleotide may preferably hybridize under sequence conditions of the synthesis phase predominantly sequence-specifically to the template strand via complementary binding.
- a block oligonucleotide when attached to the template strand, prevents the polymerase from reading the template strand beyond that oligonucleotide.
- oligonucleotide structures are suitable for this purpose.
- the selection of the oligonucleotide structure, the polymerase and the reaction conditions are based on the fact that the progressive synthesis is hindered or blocked by the polymerase.
- Oligonucleotides with several double strand stabilizing modifications typically results in the polymerase being unable to continue synthesis via the oligonucleotide binding site.
- LNA or PNA double strand stabilizing modifications
- template-complementary oligonucleotides of about 20-50 nucleotides in length with about 7-30 LNA modifications, for example, a Bst polymerase (large fragment) can prevent this oligonucleotide from detaching via polymerase-dependent strand displacement from the template.
- the length of the complete P1-ext generated during template-dependent synthesis and the length of the matching controller oligonucleotide can be chosen differently.
- the length of the controller oligonucleotide and the length of the expected fully synthesized primer extension product are matched so that the controller oligonucleotide completely covers the region synthesized by the polymerase.
- a controller oligonucleotide can completely detach the P1 -ext from the template. In the 3 ' segment of the P1 -ex, no free nucleotides remain for interaction with the template during the controlling phase (see below)
- the length of the controller oligonucleotide and the length of the expected primer extension product are matched to one another such that the length of the synthesized region of the primer extension product extends beyond the length of the controller oligonucleotide.
- the 3 ' segment of the primer extension product thus comprises a sequence segment which does not belong to the controller Oligonucleotide is checked. When the P1-Ext interacts with the controller, a double-stranded segment of P1-Ext and matrix remains, which is not checked by the controller.
- this double-stranded segment can spontaneously dissociate under the reaction conditions of the controlling phase, eg due to a temperature-induced strand opening (eg at temperatures of about 50-70 ° C).
- the length of this 3 ' segment of the primer extension product may comprise, for example, sequence lengths which lie in the following ranges: from 1 to 10 nucleotides, from 10 to 20 nucleotides, from 30 to 40 nucleotides, from 40 to 50 nucleotides, from 50 to 70 nucleotides, from 70 to 100 nucleotides.
- this double-stranded segment can not spontaneously dissociate under the reaction conditions of the controlling phase, eg due to a temperature-induced strand opening (eg at temperatures of about 50-70 ° C).
- the length of this 3 ' segment of the primer extension product may comprise, for example, sequence lengths which lie in the following ranges: more than 20 nucleotides, more than 30 nucleotides, more than 40 nucleotides, more than 50 nucleotides, more than 100 nucleotides, more than 200 nucleotides, more than 500 nucleotides.
- the maximum length can reach up to about 10,000 nucleotides.
- the aim of the controlling phase is to check the synthesized primer extension product for its agreement with the given sequence during the ongoing synthesis (real-time control).
- the correct, fully complementary primer extension products are to be synthesized in full length.
- the resulting during the synthesis of misincorporation events by the polymerase from the further extension reaction should be excluded.
- mismatches between primer extension products resulting from a polymerase during synthesis are to be prevented from lengthening on the template strand. This is done by forming a complex of such a mismatch-containing primer extension product and a controller oligonucleotide during the primer extension reaction.
- the terminal mismatch-containing primer extension products bound to the controller oligonucleotide should preferably remain in these complexes under reaction conditions.
- primer extension products in which the progress of the synthesis reaction is slowed down e.g., due to polymerase mismatch incorporation, ie, polymerase errors
- primer extension products in which the progress of the synthesis reaction is slowed down e.g., due to polymerase mismatch incorporation, ie, polymerase errors
- polymerase mismatch incorporation ie, polymerase errors
- controller oligonucleotide By repeated interactions between the controller oligonucleotide and the primer oligonucleotides and between the controller oligonucleotide and the primer Extension products (the interaction begins with the binding of the controller to the primer overhang) as they are generated, there is competition between the synthesis process and a strand displacement event by the controller oligonucleotide.
- concentration of controller oligonucleotides can be varied between 0.001 pmol / l and 50 pmol / l, in particular between 0.01 pmol / l and 10 pmol / l.
- the extent of the controller-dependent strand displacement can be influenced.
- the freely available controller oligonucleotides can interact with the second primer region (primer overhang). Among other things, interactions with complexes comprising primer extension products and template strands occur. The interaction starts from the primer overhang. This provides spatial proximity between the controller strand and the end of the double-stranded region between primer extension product / template strand. As a result, the double-stranded formation can be transferred between the controller oligonucleotide and the first primer region (sequence-dependent strand displacement). Given the sequence identity with the synthesized portion of the primer extension product, the double strand formation between the controller oligonucleotide and the primer extension product continues to expand.
- processive polymerases typically results in the primer extension reaction by the polymerase with full match of the synthesized growing strand to its template being faster than forming a double-stranded complex of primer extension product and controller oligonucleotide.
- the time delay of the enzymatic synthesis is exploited, which usually takes place in a strand extension process, when this strand comprises a mismatch as a result of a polymerase error.
- the perfect-match strands are generally synthesized faster than those that have a mismatch in the primer extension product. After a misincorporation into the growing strand, there is a temporary slowdown or even a pause in the synthesis, so that the process of double-stranding between the controller oligonucleotide and the primer extension product can detach this "paused strand" from the template before a further synthesis can take place.
- the binding of such an incomplete primer extension product to the controller oligonucleotide is preferably sufficiently stable under reaction conditions used so that this incomplete product can be removed from the further template-dependent syntheses by the polymerase. Since the controller oligonucleotide does not serve as a template, such an incomplete primer extension product will remain in complex with the controller oligonucleotide.
- the length of the controller oligonucleotide and the length of expected full primer extension product are matched so that the length of the synthesized region of the primer extension product extends beyond the length of the controller oligonucleotide.
- the 3 ' segment of the primer extension product thus comprises a sequence segment which is not checked by the controller oligonucleotide.
- the interaction of the P1-text with the controller thus leaves a double-stranded segment of P1-text and matrix.
- this double-stranded segment can spontaneously dissociate under the reaction conditions of the controlling phase, for example due to a temperature-induced strand opening (eg at temperatures of about 50-70 ° C).
- the length of this 3 ' segment of the primer extension product may comprise, for example, sequence lengths ranging from 1 to 10 nucleotides, from 10 to 20 nucleotides, from 30 to 40 nucleotides, from 40 to 50 nucleotides.
- the interaction of the controller oligonucleotide interaction with the synthesized primer extension product and the spontaneous dissociation of the 3 ' segment complex of the P1 -ext and template may result in the detachment of the primer extension product (in the complex of P1 -ext and controller-strand ) from the matrix.
- the 3 ' segment may play a functional role in subsequent analyzes / reactions.
- the complexes formed controller oligonucleotide and incomplete primer extension product are preferably sufficiently stable under the chosen reaction conditions, so that this incomplete primer extension product can be excluded from a continuation of its synthesis at the template strand or by the complex form with the controller strongly prevented the continuation of the template-dependent synthesis reaction.
- the synthesis of defective primer extension products can be prevented to full synthesis length. Because of insufficient length, such incomplete P1 text preferably does not include a required 3 ' sequence segment to participate in other or subsequent reactions. This missing 3 ' segment can be used, for example, for interaction with a probe or a probe another primer is missing. As a result, defective primer extension products can not develop the full functionality required in subsequent reactions, eg in a detection process or an amplification.
- the interaction between the controller oligonucleotide and the primer extension product depends on the complementarity between the primer extension product and the controller oligonucleotide. In case of deviations, the process of sequence-dependent strand displacement can be severely hindered.
- the higher the sequence differences between the synthesized primer extension product and the corresponding controller oligonucleotide the more the formation of a complex of controller oligonucleotide and P1 -ex is affected.
- the degree of influence can range from slight deceleration to complete stop in the progress of complex formation. For this reason, it is advantageous if the controller oligonucleotide is adapted to the desired primer extension product and is able to enter into its third region with a substantially complementary binding to the synthesized sequence segment of the primer extension product.
- the correctly synthesized primer extension product may be released from the template, for example as shown in the above embodiments.
- primer extension product in further reactions may require that certain portions of the primer extension product be in single-stranded form. This may be necessary, for example, for the binding of a primer or a probe. This embodiment can therefore be used, for example, to convert the sequences in the 3 ' segment of the primer extension product into the single-stranded state.
- controller oligonucleotides in the assay allows for both low-contamination integration into other methods of molecular analysis and combination with other methods, e.g. with amplification method or detection method.
- the specific primer extension products synthesized in a primer extension reaction can be used as a starting nucleic acid in subsequent amplification procedures.
- the primer extension reaction described herein comprises at least a first primer and at least one controller oligonucleotide.
- the product of the primer extension reaction, the primer extension product can be used, for example, in a subsequent amplification reaction, which also proceeds with the assistance of a controller oligonucleotide.
- primer extension reaction first primer and controler oligonucleotide
- Reaction conditions include, but are not limited to, buffer conditions, temperature conditions, duration of reaction, and concentrations of respective reaction components.
- the reaction comprising the synthesis of the extension products can be carried out for as long as necessary to produce the desired amount of the specific nucleic acid sequence.
- the process according to the invention is preferably carried out continuously.
- the amplification reaction proceeds at the same reaction temperature, wherein the temperature is in particular between 50 ° C and 75 ° C.
- the reaction temperature can also be variably controlled, so that individual steps of the primer extension reaction proceed at different temperatures.
- no helicases or recombinases are used in the reaction mixture to separate the newly synthesized duplexes of the nucleic acid to be amplified.
- the reaction mixture does not include biochemical energy-donating compounds such as ATP.
- the amount of nucleic acid to be amplified at the beginning of the reaction can be between a few copies and several billion copies in one run.
- the amount of template comprising a target sequence may be unknown.
- the reaction may also contain other nucleic acids which are not to be amplified. These nucleic acids may be derived from natural DNA or RNA or their equivalents. In certain embodiments, control sequences are in the same approach, which should also be amplified in parallel to the nucleic acid to be amplified.
- a molar excess of about 10 3 : 1 to about 10 15 : 1 (primer: template ratio) of the primers employed and the controller oligonucleotide may be added to the reaction mixture, which comprises template strands.
- the amount of target nucleic acids may not be known if the method of the invention is used in diagnostic applications, so that the relative amount of the primer and the controller oligonucleotide relative to the complementary strand can not be determined with certainty.
- the amount of primer added will generally be present in molar excess relative to the amount of complementary strand (template) when the sequence to be amplified is contained in a mixture of complicated long-chain nucleic acid strands. A large molar excess is preferred to improve the efficiency of the process.
- the concentrations of primer-1 and controller oligonucleotide used are, for example, in the range between 0.01 pmol / l and 100 pmol / l, in particular between 0.1 pmol / l and 100 pmol / l, in particular between 0.1 pmol / l and 50 pmol / l, in particular between 0.1 pmol / l and 20 pmol / l.
- the high concentration of components can increase the rate of amplification.
- the respective concentrations of individual components can be varied independently of one another in order to achieve the desired reaction result.
- the concentration of polymerase ranges between 0.001 pmol / l and 50 pmol / l, in particular between 0.01 pmol / l and 20 pmol / l, in particular between 0.1 pmol / l and 10 pmol / l.
- the concentration of individual dNTP substrates is in the range between 10 pmol / l and 10 mmol / l, in particular between 50 pmol / l and 2 mmol / l, in particular between 100 pmol / l and 1 mmol / l.
- the concentration of dNTP can affect the concentration of divalent metal cations. If necessary, this will be adjusted accordingly.
- divalent metal cations for example, Mg 2+ are used.
- a corresponding anion for example, CI, acetate, sulfate, glutamate, etc. can be used.
- the concentration of divalent metal cations is adapted, for example, to the optimum range for each polymerase and comprises ranges between 0.1 mmol / l and 50 mmol / l, in particular between 0.5 mmol / l and 20 mmol / l, in particular between 1 mmol / l and 15 mmol / l.
- the enzymatic synthesis is generally carried out in a buffered aqueous solution.
- buffer solutions dissolved conventional buffer substances, such as Tris-HCl, Tris-acetate, potassium glutamate, HEPES buffer, sodium glutamate in conventional concentrations can be used.
- the pH of these solutions is usually between 7 and 9.5, in particular about 8 to 8.5.
- the buffer conditions can be adapted, for example, according to the recommendation of the manufacturer of the polymerase used.
- Tm depressors eg DMSO, betaines, TPAC
- Tm depressors eg DMSO, betaines, TPAC
- Tween 20 or Triton 100 can also be added in conventional amounts to the buffer.
- EDTA or EGTA may be too Complexation of heavy metals can be added in conventional amounts.
- Polymerase stabilizing substances such as trehalose or PEG 6000 may also be added to the reaction mixture.
- the reaction mixture contains no inhibitors of the strand displacement reaction and no inhibitors of polymerase-dependent primer extension.
- the reaction mixture contains DNA-binding dyes, especially intercalating dyes, such as e.g. EvaGreen or SybrGreen.
- intercalating dyes such as e.g. EvaGreen or SybrGreen.
- Such dyes may possibly enable the detection of the formation of new nucleic acid chains.
- the reaction mixture can furthermore contain proteins or other substances which, for example, originate from an original material and which preferably do not influence the amplification.
- the reaction temperatures of the individual steps of the amplification reaction can be in the range of about 15 ° C to about 85 ° C, in particular in the range of about 15 ° C to about 75 ° C, in particular in the range of about 25 ° C to about 70 ° C.
- the reaction temperature can be optimally adjusted for each individual reaction step, so that such a temperature is brought about for each reaction step.
- the amplification reaction thus comprises a repetitive change of temperatures, which are repeated cyclically.
- reaction conditions for a plurality of reaction steps are standardized so that the number of temperature steps is less than the number of reaction steps.
- at least one of the steps of amplification occurs at a reaction temperature which differs from the reaction temperature of other steps of the amplification. The reaction is thus not isothermal, but the reaction temperature is changed cyclically.
- the lower temperature range includes, for example, temperatures between 25 ° C and 60 ° C, in particular between 35 ° C and 60 ° C, in particular between 50 ° C and 60 ° C and the upper temperature range includes, for example, temperatures between 60 ° C and 75 ° C, especially between 60 ° C and 70 ° C.
- the lower temperature range includes, for example, temperatures between 15 ° C and 50 ° C, in particular between 25 ° C and 50 ° C, in particular between 30 ° C and 50 ° C and the upper temperature range includes, for example, temperatures between 50 ° C and 75 ° C, especially between 50 ° C and 65 ° C.
- the lower temperature range includes, for example, temperatures between 15 ° C and 40 ° C, in particular between 25 ° C and 40 ° C, in particular between 30 ° C and 40 ° C and the upper temperature range includes, for example, temperatures between 40 ° C and 75 ° C, especially between 40 ° C and 65 ° C.
- the temperature can be kept constant in the respective range or can be changed as a temperature gradient (decreasing or rising).
- Any induced temperature can be maintained for a period of time, resulting in an incubation step.
- the reaction mixture may thus be incubated for a period of time during amplification at a selected temperature. This time may be of different duration for the particular incubation step and may depend on the progress of the particular reaction at a given temperature (e.g., primer extension or strand displacement, etc.).
- the time of an incubation step may comprise the following ranges: between 0.1 sec and 10,000 sec, in particular between 0.1 sec and 1000 sec, in particular between 1 sec and 300 sec, in particular between 1 sec and 100 sec.
- a temperature change By such a temperature change, individual reaction steps can preferably be carried out at a selected temperature. As a result, yields of a particular reaction step can be improved.
- a change in temperature or a temperature change between individual temperature ranges may be required several times.
- a synthesis cycle may thus comprise at least one temperature change. Such a temperature change can be performed routinely, for example, in a PCR device / thermocycler as a time program.
- an amplification method is preferred in which at least one of the steps comprising the strand displacement and at least one of the steps comprising the primer extension reactions take place simultaneously and in parallel and under the same reaction conditions.
- a primer extension reaction of at least one primer oligonucleotide e.g., of the first primer oligonucleotide
- the strand displacement with the aid of controller oligonucleotide and the one further primer extension reaction are preferably carried out in the reaction step in the upper temperature range.
- an amplification method is preferred in which at least one of the steps comprising strand displacement by the controller oligonucleotide and at least one of the steps comprising the primer extension reaction are performed at different temperatures.
- primer extension reactions of at least one primer oligonucleotide (For example, from the first primer oligonucleotide and / or second primer oligonucleotide) preferably carried out at temperature conditions in the lower temperature range.
- the strand displacement with the assistance of controller oligonucleotide preferably takes place in the reaction step in the upper temperature range.
- all steps of an amplification reaction proceed under identical reaction conditions.
- the amplification process may be carried out under isothermal conditions, i. that no temperature changes are required to carry out the process.
- the entire amplification reaction is carried out under constant temperature, i. the reaction is isothermal.
- the time of such a reaction comprises, for example, the following ranges: between 100 sec and 30,000 sec, in particular between 100 sec and 10,000 sec, in particular between 100 sec and 1000 sec.
- Individual process steps can each be carried out in succession by adding individual components.
- all reaction components necessary for the execution of an amplification are present at the beginning of an amplification in a reaction mixture.
- the start of an amplification reaction can be carried out by adding a component, e.g. by adding a nucleic acid chain comprising a target sequence (e.g., a starting nucleic acid chain), or a polymerase or divalent metal ions, or also by providing reaction conditions necessary for amplification, e.g. Setting a required reaction temperature for one or more process steps.
- a component e.g. by adding a nucleic acid chain comprising a target sequence (e.g., a starting nucleic acid chain), or a polymerase or divalent metal ions, or also by providing reaction conditions necessary for amplification, e.g. Setting a required reaction temperature for one or more process steps.
- the amplification can be carried out until the desired amount of nucleic acid to be amplified is reached.
- the amplification reaction is carried out for a time which would have been sufficient in the presence of a nucleic acid to be amplified in order to obtain a sufficient amount.
- the amplification reaction is carried out over a sufficient number of synthesis cycles (doubling times) which would have been sufficient in the presence of a nucleic acid to be amplified in order to obtain a sufficient amount.
- the reaction can be stopped by various interventions. For example, by changing the temperature (e.g., cooling or heating, for example, interfering with the function of the polymerase) or by adding a substance which stops a polymerase reaction, e.g. EDTA or formamide.
- a temperature e.g., cooling or heating, for example, interfering with the function of the polymerase
- a substance which stops a polymerase reaction e.g. EDTA or formamide.
- the amplified nucleic acid chain can be used for further analysis.
- synthesized nucleic acid chains can be analyzed by various detection methods. For example, fluorescence-labeled oligonucleotide probes can be used or sequencing methods (Sanger sequencing or next-generation sequencing), solid-phase analysis such as microarray or bead-array analysis, etc.
- the synthesized nucleic acid chain can be used as a substrate / template in further primer extension reactions.
- the progress of the synthesis reaction is monitored during the reaction. This can be done, for example, by using intercalating dyes, e.g. Sybrgreen or Evagreen, or using labeled primers (e.g., Lux primer or Scorpion primer) or using fluorescently labeled oligonucleotide probes.
- intercalating dyes e.g. Sybrgreen or Evagreen
- labeled primers e.g., Lux primer or Scorpion primer
- fluorescently labeled oligonucleotide probes e.g., fluorescently labeled oligonucleotide probes.
- the detection of the change in fluorescence during amplification is implemented in a detection step of the method.
- the temperature and the duration of this step can be adapted to the particular requirements of an oligonucleotide probe.
- the temperatures of the detection step include, for example, ranges between 20 ° C and 75 ° C, in particular between 40 and 70 ° C, in particular between 55 and 70 ° C.
- the reaction is illuminated with light of a wavelength capable of exciting a used fluorophore of the detection system (a donor or a fluorescent reporter).
- a used fluorophore of the detection system a donor or a fluorescent reporter.
- the signal detection is usually parallel to excitation, whereby the specific fluorescence signal is detected and its intensity is quantified.
- the amplification method can be used to verify the presence of a target nucleic acid chain in a biological material or diagnostic material as part of a diagnostic procedure.
- reaction conditions of at least one reaction step in which at least one allele-specific primer is to hybridize to an allele-specific sequence variant and a primer extension reaction by a polymerase is to be chosen such that a predominantly specific hybridization of such a primer to its Primer binding site can take place.
- Such conditions can also be called stringent conditions.
- the temperature in such a step is about Tm of the respective primer / primer binding site or the temperature is above such a Tm.
- the temperature may be about Tm +5 to about Tm + 15 ° C.
- the first primer oligonucleotide (primer-1) is a nucleic acid chain which includes at least the following regions:
- a first primer region in the 3 ' segment of the first primer oligonucleotide capable of substantially sequence-specific binding to a strand of nucleic acid chain to be amplified
- a second region coupled directly or via a linker, to the 5 ' end of the first primer region of the first primer oligonucleotide which has a polynucleotide Which is suitable for binding a controller oligonucleotide and promoting strand displacement (step c) by the controller oligonucleotide, wherein the polynucleotide tail remains substantially single-stranded under reaction conditions, ie, does not form a stable hairpin structure or ds structures, and preferably not copied by the polymerase.
- the total length of the first primer oligonucleotide is between 10 and 80, more preferably between 15 and 50, more preferably between 20 and 30 nucleotides or their equivalents (e.g., nucleotide modifications).
- the structure of the first primer oligonucleotide is adapted to undergo reversible binding to the controller oligonucleotide under selected reaction conditions. Furthermore, the structure of the first primer oligonucleotide is adapted to its primer function. Furthermore, the structure is adapted so that a strand displacement can be performed by means of controller oligonucleotide. Overall, structures of the first and second regions are matched to each other so that exponential amplification can be performed.
- the first and second regions of the primer are coupled in a conventional 5 ' -3 ' configuration.
- the coupling of both sections is via a 5 ' -5 ' bond such that the second region has a reverse direction from the first region.
- the coupling of areas between each other / each other is preferably covalent.
- the coupling between the first and second regions is a conventional DNA for 5'-3 '-Phosphodiester coupling. In certain embodiments, it is a 5 '-5' -Phosphodiester coupling. In certain embodiments, it is a 5 '-3' - phosphodiester linkage, wherein between adjacent terminal nucleotides or nucleotide modifications of the two regions at least one linker (eg, a C3, C6, C12 or HEG linker or abasic modification) is positioned.
- linker eg, a C3, C6, C12 or HEG linker or abasic modification
- nucleotide modifications may include different nucleotide modifications.
- individual elements of nucleotides can be modified: nucleobase and backbone (sugar content and / or phosphate content).
- modifications may be used which lack or are modified at least one component of the standard nucleotide building blocks, e.g. PNA.
- a second portion of the first primer oligonucleotide includes additional sequences that do not bind to the controller oligonucleotide. These sequences can be used for other purposes, such as binding to the solid phase. These sequences are preferably located at the 5 ' end of the polynucleotide tail.
- a first primer oligonucleotide may comprise a characteristic label.
- markings are dyes (eg FAM, TAMRA, Cy3, Alexa 488 etc.) or biotin or other groups which can be specifically bound, eg digoxigenin.
- the sequence length is between about 3-30 nucleotides, in particular between 5 and 20 nucleotides, the sequence being predominantly complementary to the 3 ' segment of a strand of the nucleic acid chain to be amplified.
- this primer region must be able to specifically bind to the complementary 3 ' segment of a second primer extension product.
- This first area should be copied in the reverse synthesis and also serves as a template for the 2nd strand.
- the nucleotide building blocks are preferably linked to each other via conventional 5 'to 3' Phosphodie bond or Phosphothioester bond.
- the first primer region preferably includes nucleotide monomers which do not or only insignificantly influence the function of the polymerase, for example:
- the 3 'OH end of this range preferably free of modifications and has a functional 3' -OH group, that can be recognized by the polymerase.
- the first primer region serves as the initiator of the synthesis of the first primer extension product in the amplification.
- the first region comprises at least one phosphorothioate compound, so that no degradation of the 3 ' end of the primer by the 3 ' exonuclease activity of polymerases can take place.
- sequence of the first region of the first primer oligonucleotide and the sequence of the second region of the controller oligonucleotide are preferably complementary to one another.
- the first primer region or its 3 ' segment can bind to the sequence segments of a target sequence.
- an allele-specific first primer is used in combination with an allele-specific controller oligonucleotide.
- the first primer region of the first primer can bind to the corresponding complementary position of a starting nucleic acid or of a nucleic acid chain to be amplified.
- a first primer region comprises at least one sequence segment which can bind specifically under specific reaction conditions to an allele-specific sequence variant of the target nucleic acid, wherein the polymerase is able to extend a perfect-match complex formed thereby, so that a first Primer extension product results.
- the position of an allele-specific sequence in the primer includes the 3 ' -terminal nucleotide.
- the position of an allele-specific sequence in the primer comprises at least one of the positions -1 to -6 nucleotides in the 3 ' terminal segment of the first region of the first primer. In another embodiment, the position of an allele-specific sequence in the primer comprises at least one of the positions from -6 to at least -15 in the 3 ' terminal segment of the first region of the first primer.
- Such a primer further comprises sequence segments which can bind in a uniform manner to all allelic variants of a target sequence in a uniform manner.
- the first region of a first allele-specific primer comprises sequence segments which are both target sequence-specific and those which are allele-specific.
- a combination of an allele-specific primer and an allele-specific controller oligonucleotide is used, wherein the first region of the first primer oligonucleotide is completely complementary to the second region of the controller oligonucleotide.
- Single allele-specific primers can be grouped together to cover all variants of a target sequence.
- Such a group of allele-specific primers comprises at least two different allele-specific primers, as a polymorphic locus at a given position in the target sequence comprises at least two sequence variants.
- the allele-specific primers are designed to perfectly match under stringent reaction conditions, preferably with their specific template, and thus use this specific perfect-match template to form the respective primer extension products under the catalytic action of the polymerase.
- 3 ' -terminal nucleotides and / or 3 ' -terminal segments of allele-specific primers can be used to discriminate variants of target sequences and are thus adapted in their sequence composition to the respective variants such that such primers adopt a perfect-match duplex form stringent conditions with the respective variant.
- Such perfect-match double strands can usually be recognized well by a polymerase and under suitable reaction conditions a primer extension occurs. The interaction of an allele-specific primer with another variant of a target sequence thus results in a mismatch double strand.
- mismatches usually lead to a delay in the extension by a polymerase or to a slowing of the overall reaction.
- allele-specific primers in the 3 ' segment may include at least one phosphorothioate linkage that protects the allele-specific primers from 3 ' -5 ' nuclease degradation by a polymerase.
- multiple allele-specific primers include sequence segments which are substantially identical for a group of allele-specific primers, as well as sequence segments which are different among the primers of a group and characteristic of the respective sequence variant of a target sequence. Including uniform sequence segments, such primers can hybridize to the respective target sequence under Christsbedinungen. Including characteristic sequence segments, a respective primer can specifically bind to a sequence variant of the target sequence to form a perfect-match double strand.
- the primers are designed so that, under the reaction conditions used, binding to a target sequence to form a perfect match double strand is preferred and binding to a target sequence to form a mismatch duplex is less preferred.
- a target sequence-specific first primer (but not an allele-specific first primer) is used in combination with an allele-specific controller oligonucleotide.
- the first primer region of the first primer can bind to the corresponding complementary position of a starting nucleic acid or of a nucleic acid chain to be amplified.
- a first primer region comprises at least one sequence segment, which preferably can bind sequence specifically under reaction conditions used to sequence segments of a target nucleic acid chain (for example comprising a start nucleic acid and / or the nucleic acid chain to be amplified), this binding being essentially independent of potentially existing sequence differences in the polymorphic locus, wherein the polymerase is capable of extending a perfect-match complex formed thereby resulting in a first primer extension product.
- the binding of such a primer essentially takes place in the sequence segment of the target nucleic acid, which is uniform for at least two allelic variants of these target nucleic acid chains.
- the primer binding preferably takes place in the sequence segment of the target nucleic acid, which is uniform for all allelic variants of this target nucleic acid.
- a resulting first primer extension product thus comprises a complementary sequence to the polymorphic locus. This sequence is in the 3 ' direction from the first primer.
- Such a primer thus comprises sequence segments which can preferably bind uniformly to all allelic variants of a target sequence in a uniform manner.
- a primer For differentiation of allelic variants to take place, such a primer must be combined with at least one allele-specific controller oligonucleotide. The allele discrimination is thus effected by the action of the controller oligonucleotide.
- the positioning of the polymorphic locus in the 3 ' direction from the primer causes its localization in the third region of the controller oligonucleotide.
- the second region of the first primer oligonucleotide The second region of the first primer oligonucleotide
- the second region of the first primer oligonucleotide is preferably a nucleic acid sequence comprising at least one polynucleotide tail which preferably remains uncopied during the synthesis reaction of the polymerase and which is capable of binding to the first region of the controller oligonucleotide.
- the segment of the second region, which predominantly undergoes this binding with the controller oligonucleotide, may be referred to as the polynucleotide tail.
- the second region of the first primer oligonucleotide must not only specifically bind the controller oligonucleotide under reaction conditions, but also participate in the process of strand displacement by means of controller oligonucleotide.
- the structure of the second region must therefore be suitable for bringing about spatial proximity between the controller oligonucleotide and the corresponding duplex end (in particular, the 3 ' end of the second primer extension product).
- the design of the structure of the second region of the first primer oligonucleotide is shown in more detail in several embodiments.
- the arrangement of the oligonucleotide segments and the modifications used are taken into account, which lead to a stop in the polymerase-catalyzed synthesis.
- the length of the second region is between 3 and 60, in particular between 5 and 40, in particular between 6 and 15 nucleotides or their equivalents.
- the sequence of the second area may be chosen arbitrarily. Preferably, it is not complementary with the nucleic acid to be amplified and / or with the second primer oligonucleotide and / or with the first region of the first primer oligonucleotide. Furthermore, it preferably contains no self-complementary segments, such as hairpins or stemmloops.
- sequence of the second region is preferably matched to the sequence of the first region of the controller oligonucleotide, so that both sequences can bind under reaction conditions.
- this bond is reversible under reaction conditions: there is thus a balance between components bound together and unbound components.
- the sequence of the second region of the first primer oligonucleotide is preferably chosen such that the number of complementary bases which can bind to the first region of the controller oligonucleotide is between 1 and 40, in particular between 3 and 20, in particular between 6 and 15 lies.
- the function of the second area is, inter alia, the binding of the controller oligonucleotide.
- this binding is preferably specific such that a second region of a first primer oligonucleotide is a specific controller Can bind oligonucleotide.
- a second region may bind more than one controller oligonucleotide under reaction conditions.
- the degree of complementarity between the second region of the first primer oligonucleotide and the first region of the controller oligonucleotide may be between 20% and 100%, in particular between 50% and 100%, in particular between 80% and 100%.
- the respective complementary regions may be positioned immediately adjacent to each other or may comprise non-complementary sequence segments therebetween.
- sequence-specific and therefore characteristic sequence segments are preferably not complementary to the target nucleic acid chain and are adapted to the sequence segments of the first region of an allele-specific controller oligonucleotide so that predominantly specific complementary duplexes between the first region of the controller oligonucleotide and the second region of the first Primer oligonucleotide can be formed.
- pair formation may be from a particular first primer and a particular controller oligonucleotide.
- the second region of the first primer oligonucleotide can thus be used for a characteristic coding, especially in multiplex analyzes.
- the second region of the first primer oligonucleotide may, in certain embodiments, include at least one Tm modifying modification.
- Tm enhancing modifications nucleotide modifications or non-nucleotide modifications
- LNA nucleotides such as LNA nucleotides, 2-amino adenosines, or MGB modifications.
- Tm-lowering modifications may also be used, such as inosine nucleotides.
- linkers eg C3, C6, HEG linkers
- the controller oligonucleotide For strand displacement, the controller oligonucleotide must be placed in close proximity to the double-stranded end of the nucleic acid to be amplified.
- This double-stranded end consists of segments of the first primer region of the first primer extension product and a correspondingly complementary 3 ' segment of the second primer extension product.
- the polynucleotide tail predominantly complements the controller oligonucleotide under reaction conditions, thereby causing a transient approach of the second region of the controller oligonucleotide and the first region of an extended primer extension product such that a complementary bond between these elements is initiated as part of a strand displacement process can.
- binding of the controller oligonucleotide to the polynucleotide tail of the first primer oligonucleotide immediately results in such contact.
- the polynucleotide tail and the first primer region of the first primer oligonucleotide must be directly coupled to each other. Thanks to such an arrangement, after a binding of a controller oligonucleotide in its first region, contact between complementary bases of the second region of the controller oligonucleotide and corresponding bases of the first primer region can occur directly, so that strand displacement can be initiated.
- structures of the second region of the first primer oligonucleotide are located between structures of the polynucleotide tail and the first primer region. After binding of a controller oligonucleotide to the polynucleotide tail, it is thus not positioned directly at the first primer region, but at a certain distance from it.
- the structures between the uncopiable polynucleotide tail and the copiable first primer region of the primer oligonucleotide can generate such a spacing.
- This distance has a value which is between 0.1 and 20 nm, in particular between 0.1 and 5 nm, in particular between 0.1 and 1 nm.
- Such structures represent, for example, linkers (e.g., C3 or C6 or HEG linkers) or segments that are not complementary to the controller oligonucleotide (e.g., in the form of non-complementary, non-copyable nucleotide modifications).
- the length of these structures can generally be measured in chain atoms. This length is between 1 and 200 atoms, in particular between 1 and 50 chain atoms, in particular between 1 and 10 chain atoms.
- the second region of the first primer oligonucleotide generally comprises sequence arrangements that cause the polymerase to stop in the synthesis of the second primer extension product after the polymerase releases the polymerase first primer area has been successfully copied. These structures are intended to allow copying of the polynucleotide Prevent tail of the second area.
- the polynucleotide tail thus preferably remains uncoupled from the polymerase.
- such structures are between the first primer region and the polynucleotide tail.
- sequence of the polynucleotide tail may include nucleotide modifications that result in the termination of the polymerase.
- a sequence segment of the second region of the first primer oligonucleotide may comprise both functions: it is both a polynucleotide tail and a polymerase-terminating sequence of nucleotide modifications.
- first blocking moiety or first stop region Modifications in the second region of the first primer oligonucleotide which result in a synthetic stop and thus leave the polynucleotide tail uncopyable are summarized in this application by the term "first blocking moiety or first stop region".
- oligonucleotide synthesis Several building blocks in oligonucleotide synthesis are known which prevent the polymerase from reading the template and lead to the termination of the polymerase synthesis.
- non-copyable nucleotide modifications or non-nucleotide modifications are known.
- There are also synthetic types / arrangements of nucleotide monomers within an oligonucleotide which result in the termination of the polymerase eg, 5 'to 5 ' or 3 'to 3 ' ).
- Primer oligonucleotides with a non-copyable polynucleotide tail are also known in the art (eg Scorpion primer structures or primers for binding to the solid phase).
- Both primer variants describe primer oligonucleotide structures which are capable of initiating the synthesis of a strand so that a primer extension reaction can take place.
- the result is a first strand, which also integrates the primer structure with tail in the primer extension product.
- the second strand is extended to the "blocking moiety / stop structure" of the primer structure.
- Both described primer structures are designed in such a way that the 5 ' portion of the primer oligonucleotide remains single-stranded and is not copied by the polymerase.
- the second region of the primer oligonucleotide comprises a polynucleotide tail that has a conventional 5 ' to 3 ' array in its entire length and includes non-copyable nucleotide modifications.
- non-copyable nucleotide modifications include, for example, 2 '-0-alkyl-RNA modifications, PNA, morpholino. These modifications may be distributed differently in the second primer region.
- the proportion of non-copyable nucleotide modifications may be between 20% and 100% in the polynucleotide tail, in particular more than 50% of the nucleotide building blocks.
- these nucleotide modifications are in the 3 ' segment of the second region and thus adjacent to the first region of the first primer oligonucleotide.
- sequence of non-copyable nucleotide modifications is at least partially complementary to the sequence in the template strand such that primer binding to the template occurs involving at least a portion of these nucleotide modifications. In certain embodiments, the sequence of non-copyable nucleotide modifications is non-complementary to the sequence in the template strand.
- the non-copyable nucleotide modifications are preferably covalently coupled to one another and thus represent a sequence segment in the second region.
- the length of this segment comprises between 1 and 40, in particular between 1 and 20 nucleotide modifications, in particular between 3 and 10 nucleotide modifications.
- the second region of the first primer oligonucleotide comprises a polynucleotide tail that has a conventional arrangement of 5 -3 'in its entire length and includes non-copyable nucleotide modifications (eg, 2 ' to 0 alkyl modifications). and at least one non-nucleotide linker (eg, C3, C6, HEG linker).
- a non-nucleotide linker has the function of covalently linking adjacent nucleotides or nucleotide modifications while at the same time site-specifically disrupting the synthesis function of the polymerase.
- non-nucleotide linker should not remove the structures of the polynucleotide tail and the first primer region too far apart. Rather, the polynucleotide tail should be in close proximity to the first primer region.
- a non-nucleotide linker is taken to mean modifications which are no longer than 200 chain atoms in length, in particular not more than 50 chain atoms, in particular not more than 10 chain atoms. The minimum length of such a linker can be one atom.
- An example of such non-nucleotide linkers are straight or branched alkyl linkers having an alkyl chain which includes at least one carbon atom, more preferably at least 2 to 30, especially 4 to 18.
- Such linkers are in oligonucleotide chemistry well known (eg, C3, C6, or C12 linker) and can be introduced during solid phase synthesis of oligonucleotides between the sequence of the polynucleotide tail and the sequence of the first region of the first primer oligonucleotide.
- Another example of such non-nucleotide linkers are linear or branched polyethylene glycol derivatives.
- a well-known example in oligonucleotide chemistry is hexaethylene glycol (HEG).
- Another example of such non-nucleotide linkers are abasic modifications (eg THF modification, as analog of d ribose).
- Such modifications are integrated into a second region, they can effectively interfere with a polymerase in its copying function during its synthesis of the second primer extension product such that segments located in the 3 'direction (Fig Modification remain uncopied.
- the number of such modifications in the second range can be between 1 and 100, in particular between 1 and 10, in particular between 1 and 3.
- the position of such a non-nucleotide linker may be at the 3 ' end of the second region, thus representing the transition from the first region to the second region of the primer oligonucleotide.
- the location of the non-nucleotide linker in the middle segment of the second region may also be used.
- the 3 ' segment of the polynucleotide tail includes at least one, in particular several, for example between 2 and 20, in particular between 2 and 10 non-copyable nucleotide modifications. These non-copyable nucleotide modifications are preferably at the junction between the first and second regions of the primer oligonucleotide.
- the second region of the primer oligonucleotide comprises a polynucleotide tail having in its entire length an array of 5 'to 3 ' - and at least one nucleotide monomer in a "reverse" array of 3 'to 5 '- including which is positioned at the transition between the first and the second region of the first primer oligonucleotide.
- the second region of the primer oligonucleotide comprises a polynucleotide tail, such polynucleotide tail consisting entirely of nucleotides which are directly adjacent to the first region of the first primer oligonucleotide in reverse order such that the coupling of the first and second primer oligonucleotides of the second area through 5 ' - 5 ' position.
- the 3 ' terminal nucleotide of the polynucleotide tail is blocked at its 3 ' OH end to prevent side reactions.
- a terminal nucleotide can be used which has no 3 ' -OH group, for example a dideoxy nucleotide.
- the corresponding nucleotide arrangement is to be adapted in the controller oligonucleotide.
- the first and the second portion of the controller oligonucleotide in 3 'to 3' arrangement have to be linked.
- the second region of the primer oligonucleotide comprises a polynucleotide tail having a conventional 5 ' to 3 ' configuration in its entire length and including at least one nucleotide modification which is not a complementary nucleobase for the polymerase, when the synthesis is performed with all natural dNTP (dATP, dCTP, dGTP, dTTP or dUTP).
- iso-dG or iso-dC nucleotide modifications can be integrated as single, but in particular more (at least 2 to 20) nucleotide modifications in the second region of the first primer oligonucleotide.
- nucleobase modifications are various modifications of the extended genetic alphabet.
- Such nucleotide modifications preferably do not support complementary base pairing with natural nucleotides, such that a polymerase (at least theoretically) does not contain a nucleotide from the series (dATP, dCTP, dGTP, dTTP or dUTP).
- nucleotide modifications should be positioned at adjacent sites.
- the stop of polymerase synthesis is effected by the lack of suitable complementary substrates for these modifications.
- Oligonucleotides with iso-dC and iso-dG, respectively can be synthesized by standard techniques and are available from several commercial suppliers (e.g., Trilink-Technologies, Eurogentec, Biomers GmbH).
- the sequence of the first region of the controller oligonucleotide can also be adapted to the sequence of such a second primer region.
- complementary nucleobases of the extended genetic alphabet can be integrated into the first region of the controller oligonucleotide accordingly during the chemical synthesis.
- iso-dG may be integrated in the second region of the first primer nucleotide, its complementary nucleotide (iso-dC-5-Me) may be placed at the appropriate location in the first region of the controller oligonucleotide.
- this blockade preferably takes place only when the polymerase has copied the first region of the first primer oligonucleotide. This ensures that a second primer extension product has an appropriate primer binding site in its 3 ' segment. This primer binding site is exposed as part of the strand displacement and is thus available for a new binding of another first primer oligonucleotide.
- the primer extension reaction remains in front of the polynucleotide tail. Because this polynucleotide tail remains single-stranded for interaction with the controller oligonucleotide and thus is available for binding, it supports the initiation of the strand displacement reaction by the controller oligonucleotide by using the oligonucleotide corresponding complementary segments of the controller oligonucleotide brings in the immediate vicinity of the appropriate duplex end. The distance between the complementary part of the controller oligonucleotide (second region) and the complementary part of the extended primer oligonucleotide (first region) is thereby reduced to a minimum. Such spatial proximity facilitates the initiation of strand displacement.
- a complementary sequence of controller oligonucleotide is now in the immediate vicinity of the appropriate duplex end. This leads to competition for binding to the first region of the first primer oligonucleotide between the strand of the controller oligonucleotide and the primer complementary template strand.
- the initiation of the nucleic acid-mediated strand displacement process occurs.
- distances between the 5 ' segment of the first primer region of the first primer oligonucleotide, which binds to a complementary strand of the template and forms a complementary duplex, and a correspondingly complementary sequence segment in the controller oligonucleotide when bound to the Polynucleotide tail of the second region of the first primer oligonucleotide in the following ranges: between 0.1 and 20 nm, in particular between 0.1 and 5 nm, in particular between 0.1 and 1 nm. In the preferred case, this distance is less than 1 nm.
- this distance corresponds to a distance of less than 200 atoms, in particular less than 50 atoms, in particular less than 10 atoms. In the preferred case, this distance is an atom.
- the distance information is for guidance only and illustrates that shorter distances between these structures are preferred. The measurement of this distance is in many cases only possible by analyzing the exact structures of oligonucleotides and measuring sequence distances or linker lengths.
- the first primer may also include additional sequence segments that are not required for interaction with the controller oligonucleotide or template strand. Such sequence segments may, for example, bind further oligonucleotides which are used as detection probes or immobilization partners when bound to the solid phase. Primer function of the first primer oligonucleotide
- the first primer oligonucleotide can be used in several partial steps. First and foremost, it performs a primer function in the amplification.
- the primer extension reaction is carried out using the second primer extension product as a template.
- the first primer oligonucleotide may use the starting nucleic acid chain as a template at the beginning of the amplification reaction. In certain embodiments, the first primer oligonucleotide may be used in the preparation / provision of a starting nucleic acid chain.
- the first primer serves as the initiator of the synthesis of the first primer extension product using the second primer extension product as template.
- the 3 ' segment of the first primer comprises a sequence which can bind predominantly complementary to the second primer extension product. Enzymatic extension of the first primer oligonucleotide using the second primer extension product as template results in the formation of the first primer extension product.
- Such a first primer extension product comprises the target sequence or its sequence parts.
- the sequence of the copiable portion of the first primer oligonucleotide is recognized as a template by the polymerase, whereby a corresponding complementary sequence is synthesized to result in a corresponding primer binding site for the first primer oligonucleotide.
- the synthesis of the first primer extension product occurs up to and including the 5 ' segment of the second primer oligonucleotide.
- this product is bound to the second primer extension product to form a double-stranded complex.
- the second primer extension product is sequence-specifically displaced from this complex by the controller oligonucleotide.
- the controller oligonucleotide binds to the first primer extension product.
- the second primer extension product can itself serve as a template for the synthesis of the first primer extension product.
- the now vacated 3 ' segment of the first primer extension product can bind another second primer oligonucleotide so that a new synthesis of the second primer extension product can be initiated.
- the first primer oligonucleotide can serve as the initiator of the synthesis of the first primer extension product starting from the starting nucleic acid chain at the beginning of the amplification.
- the sequence of the first primer is completely complementary to the corresponding sequence segment of a starting nucleic acid chain.
- the sequence of the first primer oligonucleotide is only partially complementary to the corresponding sequence segment of a starting nucleic acid chain.
- this divergent complementarity is not intended to prevent the first primer oligonucleotide to start a predominantly sequence-specific primer extension reaction.
- the respective differences in the complementarity of the first primer oligonucleotide to the respective position in the starting nucleic acid chain are preferably in the 5 ' segment of the first region of the first primer oligonucleotide, so that in the 3 ' segment a predominantly complementary base pairing and an initiation of the Synthesis is possible.
- the first 4-10 positions in the 3 ' segment should be fully complementary to the template (starting nucleic acid chain).
- the remaining nucleotide positions may differ from a perfect complementarity.
- the extent of perfect complementarity in the remaining 5 ' segment of the first region of the first primer oligonucleotide may thus range between 50% to 100%, in particular between 80% and 100%, of the base composition.
- the sequence deviations comprise 1 to a maximum of 15 positions, in particular 1 to a maximum of 5 positions.
- the first primer oligonucleotide may thus initiate synthesis from a startup nucleic acid chain.
- copyable sequence portions of the first primer oligonucleotide are copied from the polymerase such that, in subsequent synthesis cycles, a fully complementary primer binding site within the second primer extension product for binding of the first primer oligonucleotide is formed and available in subsequent synthesis cycles.
- the first primer oligonucleotide may be used in the preparation of a starting nucleic acid chain.
- a first primer oligonucleotide can bind to a nucleic acid (for example a single-stranded genomic DNA or RNA or its equivalents comprising a target sequence) predominantly / preferably sequence-specifically and initiate a template-dependent primer extension reaction in the presence of a polymerase.
- the binding position is chosen such that the primer extension product comprises a desired target sequence.
- the extension of the first primer oligonucleotide results in a nucleic acid strand which has a sequence complementary to the template.
- Such a strand can be detached from the template (eg by heat or alkali) and thus converted into a single-stranded form.
- a single-stranded nucleic acid chain can serve as a starting nucleic acid chain at the beginning of the amplification.
- Such a start nucleic acid chain comprises in its 5 ' segment the sequence portions of the first primer oligonucleotide, furthermore it comprises a target sequence or its equivalents and a primer binding site for the second primer oligonucleotide. Further steps are explained in the section "Starting nucleic acid chain".
- the synthesis of the first primer extension product is a primer extension reaction and forms a partial step in the amplification.
- the reaction conditions during this step are adjusted accordingly.
- the reaction temperature and the reaction time are chosen so that the reaction can take place successfully.
- the particular preferred temperature in this step depends on the polymerase used and the binding strength of the respective first primer oligonucleotide to its primer binding site and includes, for example, ranges from 15 ° C to 75 ° C, in particular from 20 to 65 ° C, in particular from 25 ° C to 65 ° C.
- the concentration of the first primer oligonucleotide comprises ranges from 0.01 pmol / l to 50 pmol / l, in particular from 0.1 pmol / l to 20 pmol / l, in particular from 0.1 pmol / l to 10 pmol / l.
- all steps of the amplification proceed under stringent conditions that prevent or slow down the formation of nonspecific products / byproducts.
- stringent conditions include, for example, higher temperatures, for example above 50 ° C.
- sequence-specific primer oligonucleotides are preferably used in each case for the amplification of corresponding respective target sequences.
- sequences of the first primer oligonucleotide, the second primer oligonucleotide, and the controller oligonucleotide are matched to one another such that side reactions, e.g. Primer-dimer formation, minimized.
- the sequence of the first and second primer oligonucleotides are adapted to each other such that both primer oligonucleotides are incapable of undergoing an amplification reaction in the absence of an appropriate template and / or target sequence and / or starting sequence. Start or support nucleic acid chain.
- the second primer oligonucleotide does not comprise a primer binding site for the first primer oligonucleotide and the first primer oligonucleotide does not comprise a primer binding site for the second primer oligonucleotide.
- the primer sequences comprise extended self-complementary structures (self-complement).
- the synthesis of the first and second primer extension products proceeds at the same temperature. In certain embodiments, the synthesis of the first and second primer extension products proceeds at different temperatures. In certain embodiments, synthesis of the first primer extension product and strand displacement by the controller oligonucleotide proceeds at the same temperature. In certain embodiments, synthesis of the first primer extension product and strand displacement by the controller oligonucleotide proceeds at different temperatures.
- a first competitor primer oligonucleotide competes with the first primer oligonucleotide for binding to a sequence segment of a nucleic acid sequence sequence segment comprising at least two variants of a target nucleic acid chain.
- the first primer oligonucleotide binds to the desired or expected sequence variant and is preferably extended under stringent Christsbedinungen by a polymerase.
- the first competitor oligonucleotide binds to the second potential or expected sequence variant and is preferably extended under stringent reaction conditions by a polymerase.
- the two primers thus represent allele-specific primers with regard to potential or expected sequence variants.
- the essential difference is that the competitor primer is not able to involving a allele-specific controller oligonucleotide to initiate strand separation.
- a first competitor primer oligonucleotide comprises a nucleic acid chain which includes at least the following properties:
- a first competitor primer region in the 3 ' segment of the first competitor primer oligonucleotide capable of substantially sequence-specific binding to a strand of a nucleic acid chain to be amplified, and thus capable of competing with the first primer oligonucleotide for its primer binding site ,
- a 3 ' end of the competitor primer which, following binding to the primer binding site in the target sequence, can be sequence-specifically extended by the polymerase to form a competitor-primer extension product
- the total length of the first competitor primer oligonucleotide is between 10 and 80, in particular between 15 and 50, in particular between 20 and 30 nucleotides or their equivalents (eg nucleotide modifications).
- the length of the 3 ' segment which may undergo complementary binding to an expected sequence variant of a target sequence, comprises substantially the same regions as the first region of the first primer. This ensures that both primers can competitively bind to the target sequence and this binding occurs approximately in the same temperature range.
- the competitive binding and especially the competing primer extension using allele-specific sequence segments of the target nucleic acid usually leads to a further increase in specificity.
- the structure of the first competitor primer oligonucleotide is adapted to undergo reversible binding to the controller oligonucleotide under selected reaction conditions.
- the first competitor primer comprises sequence segments which are said to be complementary to the first region of the controller oligonucleotide.
- this first competitor oligonucleotide can not occur as an initiator of strand displacement by a controller oligonucleotide.
- the first competitor primer oligonucleotide is a DNA oligonucleotide with a conventional 5 'to 3' arrangement of nucleotides.
- a competitor primer oligonucleotide includes additional sequences that do not bind to the controller oligonucleotide. These sequences can be used for other purposes, such as binding to the solid phase. These sequences are preferably located at the 5 ' end of the 3 ' segment.
- the sequence length is between about 15-30 nucleotides, in particular between 5 and 20 nucleotides, wherein the sequence is predominantly complementary to the 3 ' segment of a strand of the amplification to be repressed allele variant of a target nucleic acid.
- the first primer region may include nucleotide monomers which do not or only insignificantly affect the function of the polymerase, for example:
- an allele-specific first primer is used in combination with an allele-specific controller oligonucleotide and an allele-specific competitor primer oligonucleotide.
- a controller oligonucleotide ( Figures 2, 7-24, 29) comprises:
- a first single-stranded region which can bind to the polynucleotide tail of the second region of the first primer oligonucleotide A second single-stranded region which can bind to the first region of the first primer oligonucleotide essentially complementary
- a third single-stranded region which is substantially complementary to at least one segment of the extension product of the first primer extension product
- controller oligonucleotide does not serve as a template for primer extension of the first or second primer oligonucleotide.
- the sequence of the third region of the controller oligonucleotide is adapted to the sequence of the nucleic acid to be amplified, since this is a template for the order of the nucleotides in the extension product of a first primer.
- the sequence of the second region of the controller oligonucleotide is adapted to the sequence of the first primer region.
- the structure of the first region of the controller oligonucleotide is adapted to the sequence of the second region of the first primer oligonucleotide, especially the nature of the polynucleotide tail.
- a controller oligonucleotide may also include other sequence segments that do not belong to the first, second or third region.
- these sequences can be attached as flanking sequences at the 3 ' and 5 ' ends.
- these sequence segments do not interfere with the function of the controller oligonucleotide.
- the structure of the controller oligonucleotide preferably has the following properties:
- the individual areas are covalently bonded to each other.
- the binding can be done for example via conventional 5 ' -3 ' bond.
- a phospho-diester bond or a nuclease-resistant phospho-thioester bond can be used.
- a controller oligonucleotide may bind by its first region to the polynucleotide tail of the first primer oligonucleotide, which binding is mediated primarily by hybridization of complementary bases.
- the length of this first region is 3 to 80 nucleotides, in particular 4 to 40 nucleotides, in particular 6 to 20 nucleotides.
- the degree of sequence match between the sequence of the first region of the controller oligonucleotide and the sequence of the second region of the first primer oligonucleotide may be between 20% and 100%, in particular between 50% and 100%, in particular between 80% and 100%.
- the binding of the first region of the controller oligonucleotide should preferably be made specifically to the second region of the first primer oligonucleotide under reaction conditions.
- the sequence of the first region of the controller oligonucleotide is preferably chosen such that the number of complementary bases that can bind to the second region of the first primer oligonucleotide complementary between 1 and 40, in particular between 3 and 20, in particular between 6 and 15 lies. Since the controller oligonucleotide is not a template for the polymerase, it may include nucleotide modifications that do not support polymerase function, which may be both base modifications and / or sugar-phosphate backbone modifications.
- the controller oligonucleotide may include, for example, in its first region nucleotides and / or nucleotide modifications selected from the following list: DNA, RNA, LNA ("locked nucleic acids”: analogs having 2 ' -4 ' bridge linkage in the sugar moiety).
- UNA locked Nucleic acids: no bond between 2 '-3' -atoms of the sugar moiety
- PNA "peptide nucleic acids” analogs
- PTO phosphorothioate
- morpholino analogs 2 '-0-alkyl-RNA modifications (such as 2 '-OMe, 2' -0 propargyl, 2 '-0- (2-methoxyethyl), 2' -0-propyl-amine), 2 - halogen-RNA, 2 '-amino-RNA, etc.
- Nucleotides or nucleotide modifications are linked to one another, for example, by conventional 5 ' -3 ' or 5 ' -2 ' binding.
- a phospho-diester bond or a nuclease-resistant phospho-thioester bond can be used.
- the controller oligonucleotide may include nucleotides and / or nucleotide modifications in its first region, the nucleobases being selected from the following list: adenines and their analogs, guanines and its analogs, cytosines and its analogs, uracil and its analogs, thymines and its analogues, inosine or other universal bases (eg nitroindole), 2-amino-adenine and its analogues, iso-cytosines and its analogues, iso-guanines and its analogues.
- nucleobases being selected from the following list: adenines and their analogs, guanines and its analogs, cytosines and its analogs, uracil and its analogs, thymines and its analogues, inosine or other universal bases (eg nitroindole), 2-amino-adenine and its analogues, iso-cytosines and
- the controller oligonucleotide may include in its first region non-nucleotide compounds selected from the following list: Intercalating substances which may affect the binding strength between the controller oligonucleotide and the first primer oligonucleotide, e.g. MGB, naphthalene etc. The same elements can also be used in the second region of the first primer.
- the controller oligonucleotide may include in its first region non-nucleotide compounds, e.g. Linkers such as C3, C6, HEG linkers which link individual segments of the first region together.
- non-nucleotide compounds e.g. Linkers such as C3, C6, HEG linkers which link individual segments of the first region together.
- the controller oligonucleotide may bind by means of its second region to the first primer region of the first primer oligonucleotide, the binding being mediated essentially by hybridization of complementary bases.
- the length of the second region of the controller oligonucleotide is matched to the length of the first region of the first primer oligonucleotide and is preferably consistent therewith. It is between about 3-30 nucleotides, in particular between 5 and 20 nucleotides.
- the sequence of the second region of the controller oligonucleotide is preferably complementary to the first region of the first primer oligonucleotide. The degree of complementarity is between 80% and 100%, in particular between 95% and 100%, in particular at 100%.
- the second region of the controller oligonucleotide preferably includes nucleotide modifications which prevent the polymerase on the extension of the first primer oligonucleotide, but do not block the formation of complementary double strands, or not substantially prevent, for example, 2 '-0-alkyl-RNA analogues (eg, 2' -0-Me, 2 '-0- ( 2-methoxyethyl), 2 '-0- propyl, 2' -0-propargyl nucleotide modifications), LNA, PNA or morpholino nucleotide modifications.
- Single nucleotide monomers are preferably linked via 5 ' -3 ' bond, but an alternative 5 ' -2 ' bond between nucleotide monomers may also be used.
- the sequence length and nature of the first and second regions of the controller oligonucleotide are preferably selected such that binding of these regions to the first primer oligonucleotide is reversible under reaction conditions, at least in one reaction step of the process. This means that the controller oligonucleotide and the first primer oligonucleotide can bind specifically to each other, but this bond should not lead to the formation of a permanently stable under reaction conditions complex of both elements.
- an equilibrium between a bound complex form of controller oligonucleotide and the first primer oligonucleotide and a free form of individual components under reaction conditions should be sought or made possible at least in one reaction step. This ensures that at least a portion of the first primer oligonucleotides can be in free form under reaction conditions and can interact with the template to initiate a primer extension reaction. On the other hand, it will be ensured that corresponding sequence regions of the controller oligonucleotide are available for binding with an extended primer oligonucleotide.
- the proportion of free, single-stranded and thus reactive components can be influenced: by lowering the temperature, first primer oligonucleotides bind to the controller oligonucleotides, so that both participants bind a complementary double-stranded complex.
- concentration of single-stranded forms of individual components can be lowered.
- An increase in temperature can lead to the dissociation of both components into single-stranded form.
- the concentration of single-stranded forms in the reaction mixture can thus be influenced.
- desired reaction conditions can be brought about during corresponding reaction steps. For example, by using temperature ranges approximately at the level of the melting temperature of complexes of controller oligonucleotide / first primer oligonucleotide portions of each free forms of individual components can be influenced.
- the temperature used increases destabilizing complexes comprising controller oligonucleotide / first primer oligonucleotide such that, during this reaction step, individual complex components become, at least temporarily, single-stranded, thereby being able to interact with other reactants.
- a first sequence region of the controller oligonucleotide may be released from the double-stranded complex with a non-extended first primer, and thus may interact with the second sequence region of an extended first primer oligonucleotide, thereby initiating strand displacement.
- release of a first, non-extended primer oligonucleotide from a complex comprising controller oligonucleotide / first primer oligonucleotide results in the first primer region becoming single-stranded and thus able to interact with the template such that primer extension by a polymerase can be initiated.
- the temperature used does not have to correspond exactly to the melting temperature of the complex of controller oligonucleotide / first primer oligonucleotide. It is sufficient if the temperature in a reaction step is approximately in the range of the melting temperature.
- the temperature in one of the reaction steps comprises ranges of Tm +/- 10 ° C, in particular Tm +/- 5 ° C, in particular Tm +/- 3 ° C of the complex of controller oligonucleotide / first primer oligonucleotide.
- Such a temperature can be set, for example, in the context of the reaction step, which comprises a sequence-specific strand displacement by the controller oligonucleotide.
- reaction conditions are maintained over the entire duration of the amplification reaction in which there is equilibrium between a complex oligonucleotide-controller design and the first primer Oligonucleotide and a free form of individual components is possible.
- the ratio between a complex form of controller oligonucleotide and the first primer oligonucleotide and free forms of individual components can be influenced both by reaction conditions (eg temperature and Mg 2+ concentration) and by structures and concentrations of individual components.
- the sequence length and nature of the first and second regions of the controller oligonucleotide are, in certain embodiments, chosen such that under given reaction conditions (eg, in the strand displacement displacement step by the controller oligonucleotide) the ratio between a proportion of free controller oligonucleotide and a portion of a controller oligonucleotide complexed with a first primer oligonucleotide comprises the following ranges: from 1: 100 to 100: 1, more preferably from 1:30 to 30: 1, more preferably from 1:10 to 10: 1.
- the ratio between a proportion of a free first primer oligonucleotide and a proportion of a first primer oligonucleotide complexed with a controller oligonucleotide comprises ranges of from 1: 100 to 100: 1, more preferably from 1:30 to 30: 1, more preferably from 1:10 to 10: 1.
- the concentration of the first primer oligonucleotide is higher than the concentration of the controller oligonucleotide. This results in an excess of the first primer in the reaction and the controller oligonucleotide must be released for its effect of binding with the first primer by choosing the appropriate reaction temperature. In general, this is done by raising the temperature to sufficient levels of free forms of the controller oligonucleotide.
- the concentration of the first primer oligonucleotide is lower than the concentration of the controller oligonucleotide.
- the concentration of the first primer oligonucleotide is lower than the concentration of the controller oligonucleotide.
- the controller oligonucleotide may bind by means of its third region to at least one segment of the specifically synthesized extension product of the first primer oligonucleotide. Binding is preferably by hybridization of complementary bases between the controller oligonucleotide and the extension product synthesized by the polymerase.
- the sequence of the third region should preferably have a high complementarity to the extension product. In certain embodiments, the sequence of the third region is 100% complementary to the extension product.
- the binding of the third region is preferably carried out on the segment of the extension product, which connects directly to the first region of the first primer oligonucleotide.
- the segment of the extension product is preferably in the 5 ' segment of the entire extension product of the first primer oligonucleotide.
- the binding of the third region of the controller oligonucleotide preferably does not occur over the entire length of the extension product of the first primer oligonucleotide.
- a segment remains unbound at the 3 ' end of the extension product.
- This 3 ' -terminal segment is necessary for the binding of the second primer oligonucleotide.
- the length of the third region is adapted accordingly so that the third region binds to the 5 ' -terminal segment of the extension product on the one hand, while on the other hand does not bind the 3 ' -step segment of the extension product.
- the total length of the third region of the controller oligonucleotide is from 2 to 100, in particular from 6 to 60, in particular from 10 to 40 nucleotides or their equivalents.
- the controller oligonucleotide may enter into a complementary bond with the segment of the extension product over that length, thereby displacing this 5 ' segment of the extension product from binding with its complementary template strand.
- the length of the 3 ' -terminal segment of the extension product which is not bound by the controller oligonucleotide comprises, for example, ranges between 5 and 200, in particular between 5 and 100, in particular between 5 and 60 nucleotides, in particular between 10 and 40, in particular between 15 and 30 nucleotides.
- This 3 ' segment of the extension product is not displaced from the controller oligonucleotide from binding with the template strand. Even with a fully bound third region of the controller oligonucleotide to its complementary segment of the extension product, the first primer extension product may remain bound to the template strand via its 3 ' -terminal segment.
- the bond strength of this complex is preferably chosen so that it can dissociate spontaneously under reaction conditions (step e), for example. This may be recordable, be achieved by that the melting temperature of the complex is from the 3 '- perennialn segment of the extension product of the first primer oligonucleotide and its template strand approximately in the range of the reaction temperature or below the reaction temperature at a corresponding reaction step (reaction step e). With little stability of this complex in the 3 ' segment of the extension product, complete binding of the third region of the controller oligonucleotide to the 5 ' segment of the extension product results in rapid dissociation of the first primer extension product from its template strand.
- the controller oligonucleotide as a whole has a suitable structure to perform its function: under appropriate reaction conditions, it is capable of sequence-specific displacement of the extended first primer oligonucleotide from binding with the template strand, thereby converting the template strand into single-stranded form, and thus for further binding with a novel first primer oligonucleotide and its target sequence-specific extension by the polymerase.
- regions one, two and three of the controller oligonucleotide should be predominantly in single-stranded form under reaction conditions. Therefore, double-stranded self-complementary structures (eg hairpins) should be included in these As far as possible, they can be avoided since they can reduce the functionality of the controller oligonucleotide.
- double-stranded self-complementary structures eg hairpins
- the controller oligonucleotide should not appear as a template in the method of the invention, therefore the first primer oligonucleotide, when attached to the controller oligonucleotide under reaction conditions, should not be extended by the polymerase.
- the 3 ' end of the first primer oligonucleotide does not remain elongated when the first primer oligonucleotide binds to the controller oligonucleotide under reaction conditions.
- the degree of blockage / inhibition / slowing / aggravation of the reaction may be between complete expression of this property (e.g., 100% blockage under given reaction conditions) and a partial expression of this property (e.g., 30-90% blockade under given reaction conditions).
- the nucleotide modifications may include base modifications and / or sugar-phosphate-residue modifications.
- the sugar-phosphate modifications are preferred because any complementary sequence of a controller oligonucleotide can be assembled by combining with conventional nucleobases.
- the nucleotides with modifications in the sugar-phosphate residue, which can lead to hindrance or blockage of the synthesis of the polymerase include, for example: 2 '-0-alkyl modifications (eg, 2' -0-methyl, 2 '-0- (2-methoxyethyl), 2 '-0-propyl, 2' -0-propargyl nucleotide modifications), 2 '-amino-2' -Deoxy- nucleotide modifications, 2 'amino-alkyl-2' -Deoxy- Nucleotide modifications, PNA, morpholino modifications, etc.
- 2 '-0-alkyl modifications eg, 2' -0-methyl, 2 '-0- (2-methoxyethyl), 2 '-0-propyl, 2' -0-propargyl nucleotide modifications
- 2 '-amino-2' -Deoxy- nucleotide modifications e.g, 2'-alkyl modifications
- the blockade can be accomplished by either a single nucleotide modification or only by coupling multiple nucleotide modifications in series (e.g., as a sequence fragment consisting of modified nucleotides). For example, at least 2, in particular at least 5, in particular at least 10, of such nucleotide modifications can be coupled side by side in the controller oligonucleotide.
- a controller oligonucleotide may comprise a uniform type of nucleotide modifications or may comprise at least two different types of nucleotide modification.
- nucleotide modifications in the controller oligonucleotide is preferably intended to prevent the polymerase from extending the 3 ' end of a first primer oligonucleotide bound to the controller oligonucleotide.
- nucleotide modifications are located in the second region of the controller oligonucleotide.
- nucleotide modifications are located in the third region of the controller oligonucleotide.
- nucleotide modifications are located in the second and third regions of the controller oligonucleotide.
- the second region of the controller oligonucleotide consists of at least 20% of its positions from such nucleotide modifications, in particular at least 50%.
- the third region of the controller oligonucleotide consists of at least 20% of its positions from such nucleotide modifications, in particular at least 50%, in particular at least 90%.
- the entire third region comprises nucleotide modifications that prevent a polymerase from extending a primer bound to such a region using the controller oligonucleotide as a template.
- the entire third and second regions include such nucleotide modifications.
- the entire first, second, and third regions include such nucleotide modifications.
- the controller oligonucleotide may consist entirely of such nucleotide modifications.
- Such modified controller oligonucleotides can be used, for example, in multiplex analyzes in which further primers are used. This is to prevent inadvertent primer extension reactions on one or more controller oligonucleotides.
- sequence of nucleobases from these nucleotide modifications is adapted to the requirements of the sequence in each area.
- the remaining portion may be natural nucleotides, or nucleotide modifications that do not or only marginally inhibit polymerase function, eg, DNA nucleotides, PTO nucleotides, LNA nucleotides, RNA nucleotides.
- further modifications for example base modifications such as 2-amino-adenosine, 2-aminopurines, 5-methyl-cytosines, inosines, 5-nitroindoles, 7-deaza-adenosine, 7-deaza-guanosine, 5-propyl-cytosine, 5 Propyl uridine or non-nucleotide modifications such as dyes, or MGB modifications, etc.
- base modifications such as 2-amino-adenosine, 2-aminopurines, 5-methyl-cytosines, inosines, 5-nitroindoles, 7-deaza-adenosine, 7-deaza-guanosine, 5-propyl-cytosine, 5 Propyl uridine or
- a segment of the controller oligonucleotide having nucleotide modifications that prevent extension of the 3 ' end of a first primer oligonucleotide bound to the controller oligonucleotide by the polymerase is termed a "second blocking moiety".
- the length of this segment may include from 1 to 50 nuclide modifications, especially between 4 and 30.
- this segment may be located in the controller oligonucleotide such that the 3 ' end of the bound first primer Oligonucleotide lies in this segment.
- this segment can span regions two and three.
- additional blocking moieties may be introduced, for example, a fourth blocking moiety which may be at the same position in the controller oligonucleotide as the second blocking unit or a deviating position.
- the fourth blocking unit may lie in the 5 ' direction from the second blocking unit.
- the primer blockade by such a fourth blocking moiety follows the same principle as that of the second blocking moiety: a primer which is capable of complementarily binding to the controller oligonucleotide is not extended by polymerase.
- the controller oligonucleotide is prevented from serving as a template for other primers, eg a competitor primer.
- a segment of the controller oligonucleotide with nucleotide modifications which prevent the extension of the 3 ' end of a further primer oligonucleotide bound to the controller oligonucleotide (eg a competitor primer oligonucleotide) by the polymerase is termed a “fourth blocking" Unit ".
- the composition of such a "fourth blocking unit” can be carried out analogously to the "second blocking unit".
- no linker structures or spacer structures such as C3, C6, HEG linkers, are used to prevent the 3 ' end extension of a first primer oligonucleotide bound to the controller oligonucleotide.
- the controller oligonucleotide may comprise, in addition to regions one, two and three, further sequence segments which, for example, flank the abovementioned regions in the 5 ' segment or 3 ' segment of the controller oligonucleotide.
- sequence elements may be used, for example, for other functions, such as interaction with probes, binding to a solid phase, etc. Such regions preferably do not interfere with the function of regions one to three.
- the length of these flanking sequences may be, for example, between 1 to 50 nucleotides.
- a controller oligonucleotide may comprise at least one element for immobilization on a solid phase, eg a biotin residue.
- a controller oligonucleotide may include at least one element for detection, eg, a fluorescent dye.
- the strand displacement of the template strands is influenced by newly synthesized strands.
- the strand displacement and / or separation is either slowed down quantitatively or completely eliminated. It is thus not at all or less often the transfer of primer binding sites in the single-stranded state. Thus, there are no or fewer primer binding sites available for a new interaction with primers. Thus, the system of both primer extension products is rarely put into an active state or an active state is not reached.
- the efficiency of the double-stranded opening of the newly synthesized primer extension products after each individual synthesis step affects the potentially achievable yields in subsequent cycles: the fewer free / single-stranded primer binding sites of a nucleic acid chain to be amplified at the beginning of a synthesis step The lower the number of newly synthesized strands of the nucleic acid chain to be amplified in this step. In other words, the yield of a synthesis cycle is proportional to the amount of primer binding sites available for interaction with corresponding complementary primers. Overall, this can be realized a control circuit.
- This control circuit corresponds to a real-time / on-line control of synthesized fragments: the sequence control takes place in the reaction mixture while the amplification takes place.
- This sequence control follows a predetermined pattern and the oligonucleotide system (by strand-opening action of controller oligonucleotide) can decide between "correct” and "non-correct” states without external interference. In the correct state, the synthesis of sequences is continued; in the incorrect state, the synthesis is either slowed down or completely prevented. The resulting differences in the yields of "correct” and “incorrect” sequences after each step affect the entire amplification comprising a variety of such steps.
- a target sequence specific controller oligonucleotide is preferably constructed in such a way that it is able to participate in the amplification of at least one predefined sequence variant of a target sequence.
- an amplification system comprising at least one controller oligonucleotide is designed such that the expected position of an allelic variant of a target sequence corresponds to a corresponding segment or a corresponding position in the controller oligonucleotide.
- An allele-specific controller oligonucleotide is preferably constructed such that it is capable of preferentially effecting the amplification of a sequence variant of a target sequence (eg, allele 1), wherein in another sequence variant of the same target sequence (eg, allele 2 ) the amplification does not proceed at all or only with reduced efficiency or does not take place in the given time, or results in a yield of amplification products which is insufficient for a detection.
- a target sequence eg, allele 1
- another sequence variant of the same target sequence eg, allele 2
- An allele-specific controller oligonucleotide is thus not only target-specific, but also allele-specific.
- Such a controller oligonucleotide thus comprises target sequence-specific sequence segments as well as allele-specific sequence segments.
- a controller oligonucleotide comprises at least one sequence segment having a sequence composition complementary to a specific allelic variant of a target sequence. Furthermore, a controller oligonucleotide preferably comprises at least one sequence segment which comprises a complementary sequence which is identical for all sequence variants of a target sequence. In certain embodiments, a controller oligonucleotide comprises at least one sequence segment capable of complementarily binding to a variant of a polymorphic locus of a target sequence.
- multiple controller oligonucleotides are provided, each comprising allele-specific sequence segments.
- the length of a sequence segment of a controller oligonucleotide which is completely complementary to the polymorphic locus of a starting nucleic acid chain can comprise regions of one nucleotide of up to 100 nucleotides, in particular of one nucleotide of up to 50 nucleotides, in particular of one nucleotide of up to 20 nucleotides.
- the length of at least one sequence segment of a controller oligonucleotide which is complementary to uniform sequence segments of a target sequence may comprise the following ranges: from 4 to 100 nucleotides, in particular from 6 to 100 nucleotides, in particular from 8 to 50 nucleotides.
- a sequence segment of a controller oligonucleotide that is complementary to at least one variant of a polymorphic locus of a target sequence is located in the third region of the controller oligonucleotide.
- a sequence segment of a controller oligonucleotide that is complementary to at least one variant of a polymorphic locus of a target sequence is located in the second region of the controller oligonucleotide.
- a sequence segment of a controller oligonucleotide that is complementary to at least one variant of a polymorphic locus of a target sequence is partially and / or completely located in the second and third regions of the controller oligonucleotide.
- the position of allele-specific sequence segments of a controller oligonucleotide can thus be divided into three groups.
- the first group comprises allele-specific sequence segments which are detected in both the first primer oligonucleotide and the controller oligonucleotide. This position thus at least partially encompasses the second region of the controller oligonucleotide and the first region of the first primer oligonucleotide.
- the second group comprises allele-specific corresponding sequence segments which are only covered by the controller oligonucleotide, both primers (the first primer and the second primer) are only target sequence specific but not allele specific.
- the position thus comprises, at least in part, the third region of the controller oligonucleotide which is intended to bind complementarily to the 5 ' segment of the portion of the first primer extension product synthesized by the polymerase.
- the third group comprises allele-specific sequence segments which are detected in both the second primer oligonucleotide and the controller oligonucleotide. This position thus at least partially encompasses the third region of the controller oligonucleotide predominantly in the 5 ' segment of the controller oligonucleotide.
- allelic variants of a target sequence encompasses different mechanisms in these groups, which, for example, must be taken into account when choosing reaction conditions.
- primers play an essential role in discrimination.
- the complementary primer binding to a corresponding primer binding site of an allelic variant of the target sequence and initiation of a synthesis of a primer extension product by the polymerase determine the extent of the different amplifications.
- the controller oligonucleotide interacts only with the first primer (first group) and with the complementary sequence segment to the 3 ' segment of the second primer (third group).
- the successful strand displacement by the controller oligonucleotide thus depends primarily on the corresponding complementary design of these moieties of primers and the controller oligonucleotide.
- the synthesized segment content of the respective primer Extension product which lies between both primers represents a uniform sequence composition for an allelic variant of a common target sequence. For this reason, it is advantageous to carry out the amplification under stringent hybridization conditions which promote allele-specific initiation of a synthesis. Use of another allele-specific competitor primer can further enhance specific initiation of the synthesis.
- the initiation of primer extension product synthesis plays a secondary role, as the primers used bind to primer binding sites that are a consistent composition for all potential allelic variants of a target sequence.
- the discrimination takes place only with the participation of the controller oligonucleotide, which participates by sequence-specific or predominantly specific strand displacement in the separation of the first and the second primer extension product.
- a fully complementary sequence of the third region of the controller oligonucleotide is preferably used which can form a perfect match with at least one allelic variant of the target sequence.
- the amplification of different allelic variants thus requires in this embodiment a combination of one allele-specific controller oligonucleotide.
- a deviation from fully-complementary sequence compositions leads to deviating amplification efficiencies.
- the first primer extension product consisting predominantly of DNA
- the second primer extension product also comprising DNA. Allele-specific sequence design of this sequence segment of the controller oligonucleotide corresponding to an allelic variant allows a perfect match / perfect binding to the first primer extension product for both competing strands.
- a controller oligonucleotide is capable of successfully displacing the second primer extension product from its binding with the first primer extension product with its corresponding sequence segment. The separation of both primer extension products allows for exponential amplification.
- the sequence segment corresponding to an allelic variant lies in the third region of the controller oligonucleotide, which comprises predominantly or exclusively DNA monomers.
- sequence segment corresponding to an allelic variant lies in the third region of the controller oligonucleotide, which comprises both DNA and DNA modifications.
- the sequence segment corresponding to an allelic variant lies in the third region of the controller oligonucleotide, which comprises predominantly or exclusively DNA modifications.
- the sequence segment corresponding to an allelic variant lies in the third region of the controller oligonucleotide, which comprises predominantly or exclusively DNA modifications.
- modifications can have an effect on binding of the controller oligonucleotide to allele-specific variates of primer - exercise extension products.
- the segment of a controller oligonucleotide that corresponds to an allele variant lies in the third region of the controller oligonucleotide, wherein this segment of the strand of the controller oligonucleotide is predominantly composed of DNA nucleotides.
- this segment lies in the 5 ' direction of the second blocking unit.
- the length of this segment corresponding to the polymorphic locus comprises in particular 1 to 20 nucleotides.
- the composition of the nucleotides in this fully complementary corresponding segment of the controller oligonucleotide comprises at least 70% of DNA nucleotides, in particular 80%, in particular more than 95% of DNA nucleotides.
- the corresponding position in the central region of the controller oligonucleotide strand which on both sides to this corresponding position of DNA complementary to the target sequence Surrounded by the strand of the controller oligonucleotide at least 4 DNA monomers, in particular at least 6 DNA nucleotides, in particular at least 10 DNA nucleotides in both directions of the expected SNP or point mutation.
- Such arrangements of DNA monomers around an expected SNP site or point mutation or single nucleotide allelic variant makes it possible to maintain a single-stranded conformation which is characteristic for the B-shape (so-called single strand persistence length).
- strand displacement occurs through the controller oligonucleotide using a corresponding segment comprising DNA monomers.
- a controller oligonucleotide which can form a complementary bond with the first primer extension product with its 5 ' end.
- allelic variants which comprise only one nucleobase, eg SNP or Point mutations
- the corresponding sequence segment is preferably arranged at a distance from the 5 ' end of the controller oligonucleotide, which comprises lengths of 10 to 60 nucleotides, in particular 20 to 50 nucleotides, in particular 30 to 40 nucleotides.
- DNA nucleotides as monomers of controller oligonucleotides must not result in the controller oligonucleotide being used as a template for primer extension using one of the primers employed by a polymerase used.
- DNA nucleotides for example A, C, T or G
- controller oligonucleotides which can form complementary base pairs (A: T, G: C) with the first primer extension products, generally lead to amplification reactions in good Exploit.
- the effect of a mismatch on amplification can be estimated by determining stabilities of potential duplexes comprising an allele-specific controller oligonucleotide having a defined sequence and a potential primer extension product or its moieties, eg, only the synthesized moiety of a primer extension product.
- the duplexes are formed in the absence of second primer extension products.
- the binding of such duplexes is more stable than the binding of duplexes comprising at least one mismatch position. This stability can be detected by melting temperature measurement.
- Differences between amplification reactions of allelic variants are generally greater the greater the difference in stability between a perfect-match duplex and a mismatch duplex comprising an allele-specific controller oligonucleotide and a potential first primer extension product. Such differences between reactions, for example, by those for a reaction required time to reach a certain amount of products. Such differences in the time between amplification reactions of perfect-match and mismatch allele variants can also be seen as a capacity for discrimination: the greater the time difference, the higher the discrimination between each allele variants.
- modifications in the controller oligonucleotide eg in the region of the second blocking unit for preventing the extension of the first primer or a competitor primer, a different discrimination or even tolerance to certain mismatches can take place.
- 2 '-0-alkyl modifications may be employed within the second blocking unit.
- Such nucleotide modifications can alter the conformation of a duplex (from B-form of a DNA: DNA duplex to A-like form of a DNA: RNA or DNA: mod. DNA duplex). In this case, especially in the base pairing between G: C and G: U or G: T, a change in the discrimination can take place.
- RNA the behavior of the G: U changes depending on the strand-form: in the case of RNA, a G: U base pair usually forms a sufficiently stable base pairing, in the case of DNA a G: U Mismatch usually leads to a weakening of the binding of both strands.
- 2 ' alkyl nucleotide-comprising modifications are used in the controller oligonucleotide (eg, within the second blocking moiety).
- a 2 '-0-Me Cytosine (C *) or 2' -0-Me Adenosine (A *) is used.
- Such modified nucleotides allow good discrimination between individual sequence variants (where perfectly match binding comprises C * : dG and A * : U or A * : T and mismatch includes, for example, C * : dA or A * : dC).
- allelic variants When using nucleotide modifications that allow inadequate discrimination of allelic variants, multiple allelic variants can thus be amplified simultaneously.
- a 2 '-0-Me guanosine or 2' -0-Me Uridine also universal bases such as inosine, or 5-nitro-indole monomers to be candidates for the tolerance allele composition belong.
- Such modifications of a controller oligonucleotide strand can be arranged at expected corresponding positions to particular allelic variants. Thus, this lack of discrimination in some modifications can be considered as follows:
- the variant is an allelic sequence corresponding segment in the third area of the controller oligonucleotide which 'comprises predominantly or exclusively 2 -0-alkyl modifications.
- the segment of a controller oligonucleotide corresponding to an allelic variant lies in the third region of the controller oligonucleotide, this segment of the strand of the controller oligonucleotide being composed predominantly of 2 'to 0 alkyl modifications.
- this segment is within the second blocking unit or in the 5 ' direction of the second blocking unit.
- the length of this segment corresponding to the polymorphic locus comprises in particular 1 to 20 nucleotides.
- the composition of the nucleotides in this fully complementary corresponding segment of the controller oligonucleotide comprises at least 50% while 2 '-0-alkyl modifications, more preferably 80%, in particular more than 95% 2' -0-alkyl modifications.
- the corresponding position is in the middle region of the controller oligonucleotide strand.
- This controller oligonucleotide strand is 'surrounded -0-alkyl modifications, the strand of the controller oligonucleotide at least four 2' on both sides to this position corresponding of complementary to the target sequence 2 -0-alkyl modifications, in particular at least six 2 ' -O-Alkyl modifications, in particular at least 10 2 ' -O-alkyl modifications in both directions of the expected SNP or point mutation comprises such an arrangement of DNA monomers to an expected SNP site or point
- Mutation or single nucleotide allele variant allows the maintenance of a single-stranded conformation, which can be referred to as A-like form.
- strand displacement occurs through the controller oligonucleotide using a corresponding segment comprising nucleotides with 2 'to O alkyl
- a controller oligonucleotide which can form a complementary bond with the first primer extension product with its 5 ' end.
- allelic variants which comprise only one nucleobase, eg SNP or point mutations, the corresponding sequence segment is preferably arranged at a distance from the 5 ' end of the controller oligonucleotide, which lengths of 10 to 60 nucleotides, in particular 20 to 50 nucleotides, in particular 30 to 40 nucleotides.
- Controller oligonucleotides comprising 2 '-0-alkyl modifications of cytosine can form a sufficient base pairing with dG-nucleotide at corresponding locations in the first primer extension product and thus support the amplification of such allelic variants generally.
- Controller oligonucleotides comprising 2 '-0-alkyl modifications of adenosine able to form a sufficient base pairing with dT or dU nucleotide at corresponding locations in the first primer extension product and thus support the amplification of such allelic variants generally.
- Controller oligonucleotides comprising 2 '-0-alkyl modifications of guanosine can form a sufficient base pairing with dC and dU nucleotide at corresponding locations in the first primer extension product and thus support the amplification of both allelic variants generally.
- Controller oligonucleotides comprising 2 '-0-alkyl modifications of uridine can form a sufficient base pairing with dA and dG-nucleotide at corresponding locations in the first primer extension product and thus support the amplification of both allelic variants generally.
- the displacement of the second primer extension product from binding with the first primer extension product by means of a sequence-dependent strand displacement by the controller oligonucleotide forms a partial step in the amplification.
- the reaction conditions during this step are adjusted accordingly.
- the reaction temperature and the reaction time are chosen so that the reaction can take place successfully.
- the strand displacement by the controller oligonucleotide until detachment / dissociation of the second primer extension product from binding with the first primer extension product may be spontaneous in the context of temperature dependent / temperature related separation of both primer extension products.
- Such a dissociation has a favorable effect on the kinetics of the amplification reaction and can be influenced by the choice the reaction conditions are influenced, for example by means of temperature conditions. The temperature conditions are therefore chosen such that successful strand displacement by complementary binding of the controller oligonucleotide favors dissociation of the second primer extension product from the 3 ' segment of the first primer extension product.
- the strand displacement by the controller oligonucleotide proceeds until the dissociation / dissociation of a 3 ' segment of the second primer extension product (P2.1-Ext) or the template strand (M1) from the complementary binding with the first primer.
- Extension product (P1 .1-text) In this case, this 3 ' segment of the second primer extension product (P2.1-Ext) or the template strand (M1) comprises at least one complementary region to the first primer and a complementary segment to the first primer extension product (P1 1-Ext) the enzymatic synthesis has arisen.
- the 3 ' segment of the first primer extension product (P1 .1-Ext) is in such a complex complementary hybridized to the second primer extension product (P2.1 -Ext) or to a template strand (M1).
- a new primer extension product (P1 .2) can be attached to this single-stranded sequence segment of the complex (P2.1 Ext) under reaction conditions and thus initiate a synthesis of a new first primer extension product (P1 .2-Ext) by a polymerase.
- P2.1 Ext single-stranded sequence segment of the complex
- P1 .2-Ext first primer extension product
- polymerase-induced strand displacement can also dissociate the complex (C1.1 / P1 1 -Ext / P2.1. -Ext) lead.
- the controller oligonucleotide, the temperature-dependent double strand destabilization and the strand displacement by the polymerase act synergistically and complementarily. This results in a dissociation of the 3 ' segment of the first primer Extension product (P1 .1 -EX) of complementary portions of the second primer extension product (P2.1-Ext).
- Such dissociation has a favorable effect on the kinetics of the amplification reaction and may be influenced by the choice of reaction conditions, e.g. by means of temperature conditions.
- the involvement of the polymerase-mediated synthesis-dependent strand displacement in the dissociation of P1 .1-Ext and P2.1 -xt has a favorable effect on strand separation.
- the temperature in this step includes, for example, ranges from 15 ° C to 75 ° C, especially from 30 ° C to 70 ° C, especially from 50 ° C to 70 ° C.
- the controller oligonucleotide Given the length of the first region of the controller oligonucleotide and the second region of the first primer oligonucleotide (including, for example, ranges of from 3 to 25 nucleotide monomers, more preferably from 5 to 15 nucleotide monomers), a strand displacement reaction can generally be successfully initiated. With complete complementarity of the controller oligonucleotide to corresponding portions of the first primer extension product, the controller oligonucleotide can bind to the first primer extension product except for the 3 ' segment of the first primer extension product and displace the second primer extension product. The second primer extension product thus remains in association with the 3 ' segment of the first primer extension product.
- the strength of this compound can be influenced by temperature. Upon reaching a critical temperature, this compound can decay and dissociate both primer extension products. The shorter the sequence of the 3 ' segment, the more unstable this compound and the lower the temperature which causes spontaneous dissociation.
- a spontaneous dissociation can be achieved for example in the temperature range, which is approximately at the melting temperature.
- the temperature of the strand displacement steps through the controller oligonucleotide is at about the melting temperature (Tm +/- 3 ° C) of the complex comprising the 3 ' segment of the first primer extension product that is not bound by the controller oligonucleotide , and the second primer oligonucleotide and the second primer extension product, respectively.
- the temperature of the strand displacement steps through the controller oligonucleotide is at about the melting temperature (Tm +/- 5 ° C) of the complex comprising the 3 ' segment of the first primer extension product that is not bound by controller oligonucleotide , and the second primer oligonucleotide and the second primer extension product, respectively.
- the temperature of the strand displacement steps through the controller oligonucleotide is above the melting temperature of the complex comprising the 3 ' segment of the first primer extension product other than controller oligonucleotide and the second primer oligonucleotide and the second primer extension product, respectively.
- a temperature includes temperature ranges from about Tm + 5 ° C to Tm + 20 ° C, especially from Tm + 5 ° C to Tm + 10 ° C.
- a first primer extension product comprises a 3 ' segment which is not bound by the controller oligonucleotide, and which
- Sequence lengths from 9 to about 18 nucleotides.
- spontaneous dissociation can usually be achieved already at temperature ranges between 40 ° C and 65 ° C. Higher temperatures also lead to dissociation.
- a first primer extension product comprises a 3 ' segment which is not bound by the controller oligonucleotide, and which
- Sequence lengths from 15 to about 25 nucleotides.
- spontaneous dissociation can usually be achieved already at temperature ranges between 50 ° C and 70 ° C. Higher temperatures also lead to dissociation.
- a first primer extension product comprises a 3 ' segment which is not bound by the controller oligonucleotide, and which
- Sequence lengths from 20 to about 40 nucleotides.
- a spontaneous dissociation usually already at temperature ranges between 50 ° C and 75 ° C can be achieved. Higher temperatures also lead to dissociation.
- composition of the 3 ' segment of the first primer extension product and optionally an introduction of melting temperature-influencing oligonucleotide modifications (eg MGB) or reaction conditions (eg TPAC, betaine) can influence the choice of temperature.
- An appropriate adaptation can therefore be made.
- all steps of the amplification proceed under stringent conditions that prevent or slow down the formation of nonspecific products / byproducts.
- stringent conditions include, for example, higher temperatures, for example above 50 ° C.
- the single steps of strand displacement by controller oligonucleotides proceed at the same temperature as the synthesis of the first and second primer extension products. In certain embodiments, the single steps of strand displacement by controller oligonucleotides occur at a temperature that is different from the temperature of the particular synthesis of the first and second primer extension products. In certain embodiments, synthesis of the first primer extension product and strand displacement by the controller oligonucleotide is included same temperature. In certain embodiments, synthesis of the second primer extension product and strand displacement by the controller oligonucleotide proceeds at the same temperature.
- the concentration of the controller oligonucleotide comprises ranges from 0.01 pmol / l to 50 pmol / l, in particular from 0.1 pmol / l to 20 pmol / l, in particular from 0.1 pmol / l to 10 pmol / l.
- Primer oligonucleotides comprising additional sequence segments:
- first primer and the second primer can be considered as so-called “base structure of the primer” or “minimal structure of the primer”.
- Such basic structures of oligonucleotides with primer function comprise sequence segments which are essential for the execution of the amplification reaction.
- Method are advantageous, for example, the first and second region of the first primer.
- Such a basic structure of the primer can be extended by additional, additional sequence segments.
- additional sequence segments include structures which, while not necessary for the performance of the amplification process, may nevertheless be useful for other tasks.
- Such additional sequence segments may optionally be introduced into a primer and used for further functions or reactions. This can be done by the
- Polymerase synthesized primer extension products (starting, for example, from the first and / or the second primer) can be linked to such sequences segments. This achieves integration of such additional sequence segments and primer extension products into a molecular structure. Such integration may be advantageous in certain embodiments.
- probes may be designed according to such a principle of intra-molecular binding, e.g. as part of Scorpion primers.
- sequence segments can be used to bind further
- a sequence-specific intermolecular binding can be achieved using stringent conditions. Such interactions can for example, for the binding of amplification products to a solid phase by complementary binding to immobilized oligonucleotides.
- primer barcoding Use of further sequence segments for the unique coding or sequence-specific labeling of primers and primer extension products emanating therefrom (so-called primer barcoding). This is used, for example, for NGS library preparation (Stählberg et al Nucleic Acids Res. 2016 Jun 20; 44 (11): e105). In the sequence analysis of primer extension products, such a label can be used to assign sequences later.
- spacer-sequence sequences which are not intended to bind a specific interaction partner, but serve primarily to increase the distance between adjacent sequences.
- Such additional sequences may either be positioned on the copiable portion of the primer or added to the non-clippable portion of the primer. Several factors play a role in judging whether a sequence segment is copied or not.
- nucleotide modifications used eg C3, HEG, 2 ' -Ome etc.
- positioning of the sequence segment in the respective oligonucleotide, nucleotide modifications used can decide whether or not a sequence segment is used as a template during a process step.
- an additional sequence segment is introduced into the copyable region of the primer, eg, at the 5 ' segment of the copiable portion of the second primer, so that, for example, in reading the primer sequence during a synthesis of a target sequence, additional sequence Segments are also read from the polymerase.
- the length of such additional sequence segment includes ranges of 3 to 50 nucleotides. The composition of these sequence segments leaves at this
- this sequence segment thus serves as a template for polymerase-dependent synthesis.
- this sequence segment will be
- nucleotides e.g. dA, dG, dC, dT.
- additional sequence segments may be positioned, for example, at the 5 ' terminus of the primer, which is not useful in the synthesis of specific
- Amplification fragments comprising a target sequence to be copied.
- This can be achieved, for example, by positioning one or more modifications or chemical groups which prevents polymerase from the synthesis of a complementary strand (eg HEG, C3, a segment comprising 4 to 10 nucleotides with 2 'to- Ome modifications Etc.).
- a complementary strand eg HEG, C3, a segment comprising 4 to 10 nucleotides with 2 'to- Ome modifications Etc.
- Such modification may for example be positioned at the 5 'terminus of the copyable portion of the second primer and obstruct the continuation of the synthesis.
- an HEG group may be introduced at the 5 ' end of the copiable segment of the second primer, followed by an additional sequence segment.
- an additional sequence segment may be positioned at the 5 ' terminus of the second region of the first primer. Such localization of additional sequence segments prevents synthesis of a complementary strand during regular synthesis of specific amplification products comprising a target sequence.
- the length of such additional sequence segment includes ranges of 3 to 50 nucleotides.
- the base composition may comprise, for example, natural nucleobases (A, G, C, T, U, inosine) or modifications at different positions of nucleotides (eg at the bases such as 2-amino-adenine, iso-guanine, iso-cytosines, 5-propargyl-Uridine, 5- propargyl cytosines or the sugar-phosphate backbone, such as LNA, 2 '-OMe, 2 - halogen, etc.).
- a first primer and additional sequence segments are combined to form an oligonucleotide.
- a second primer and additional sequence segments are combined to form an oligonucleotide.
- additional structures may be chosen from among
- such additional sequence segments do not interact with the first or second primer region of the first primer. In certain embodiments, such additional sequence segments do not interact with the controller oligonucleotide. In certain embodiments, such additional sequence segments do not interact with other primers in the reaction. In certain embodiments, such additional sequence segments do not interact with P1.1 ext or P2.1 ext or other amplification fragments comprising a target sequence. In certain embodiments, such additional sequence segments do not form reaction-stable double-stranded portions with the first or second region of the first primer that completely inhibit the function of the first or second region.
- such additional sequence segments do not interact with the second primer.
- such additional sequence segments do not interact with the 3 ' segment of the second primer.
- the first primer comprises at its 5 ' terminus of the second region an additional sequence segment of the first primer (variant sequence variant P1).
- This segment optionally includes a sequence of 10-50 nucleotides which does not interfere with the amplification process of target sequences (eg, does not form secondary structures with primers).
- this segment optionally comprises a sequence of about 5 to 15 nucleotides of the copiable first region of the first primer.
- the additional sequence variant P1 comprises natural nucleotides as monomers (A, C, G, T) and can potentially serve as a template for a polymerase.
- the second primer comprises at its 5 ' terminus an additional sequence segment of the second primer (variant sequence variant P2).
- This segment optionally includes a sequence of 10-50 nucleotides which does not match the
- this segment optionally comprises a sequence of about 5 to 15 nucleotides of the copyable region of the second primer.
- the additional sequence variant P2 comprises natural nucleotides as monomers (A, C, G, T) and can potentially serve as a template for a polymerase.
- oligonucleotides comprise a first primer and
- Oligonucleotides comprising only a first primer, or oligonucleotides comprising only a second primer.
- the generation and / or amplification of nonspecific primer-dimer structures may be delayed.
- the formation of by-products comprising no target sequence can be reduced or retarded.
- the premature consumption of primers can be reduced or delayed.
- the use of such oligonucleotides is advantageous if primer dimers comprising first primers (PD P1) or primer dimers comprising second primers (PD P2) are produced by secondary reactions and lead to premature consumption of primers in the reaction.
- primers having such additional structures are advantageous in certain embodiments if nonspecific reactions are observed in an amplification reaction.
- Such side reactions may be favored by several factors, including but not limited to:
- oligonucleotides comprising a first primer and additional sequence variant P1 or oligonucleotides comprising a second primer and additional sequence variant P2 represent a further possibility for delaying certain side reactions.
- primer oligonucleotides with additional sequence segments are shown.
- additional sequence segments are used which do not participate in the specific amplification of a target sequence and contribute to the delay of side reactions.
- oligonucleotides comprising a first primer and additional sequence variant P1 and oligonucleotides comprising a second primer and additional sequence variant P2 are used.
- an oligonucleotide in addition to a primer structure that is advantageous for the specific amplification of a target sequence (this structure may also be referred to as a "base structure” or “minimal structure”), also includes additional, additional sequence sequences. Segments may include (eg additional sequence variant P1 or additional sequence variant P2). Such additional sequence segments may provide a variety of different other beneficial properties.
- Fig. 1 shows the sequence components of a preferred embodiment of the invention.
- Primer 1 .1 can bind with its first region (in 3 ' segments) to the respective primer binding site on the template strand (M1 .1) predominantly complementary.
- the polynucleotide tail (primer overhang) of the second region does not bind to the template strand (M1 .1).
- the controller (1 .1.) Comprises a first, second and third area.
- FIG. 2 schematically illustrates the topography of the complete primer extension product (P1-Ext.), Wherein the extension product comprises a region formed by primer 1 .1 and a segment synthesized by the polymerase.
- the synthesis of a P1-ext primer extension product is shown schematically in FIG.
- the synthesis progress is in this case stopped by a block oligonucleotide sequence-specific.
- the primer / controller complex is stable under the reaction conditions used during the synthesis phase.
- the synthesis of the P1-Ext by the polymerase goes to the block oligonucleotide (B 1.1), so that the length of the synthesized segment of the P1-Ext is limited.
- the sequence-specific control of primer extension is mediated in particular by the binding of the controller oligonucleotide.
- the controller binding to the primer extension product during the control phase is shown schematically in Figure 4, where A) the release of the controller from the complex: primer / controller; B-C), the binding of the controller to the second region of the primer on the primer extension product, and D-E) illustrates the sequence-specific strand displacement by the controller to release the template strand.
- FIG. 5 schematically shows a probe binding to the primer extension product after its release from the template strand. Release from the template strand allows the 3 ' segment of the P1-Ext to interact with another oligonucleotide, such as a fluorescent probe (S1 .1), or other primers or an affinity probe. For example, a binding can lead to the increase of a fluorescence signal.
- a fluorescent probe S1 .1
- an affinity probe for example, a binding can lead to the increase of a fluorescence signal.
- a complementary to the 3 ' segment of the primer extension product formed oligonucleotide with a quencher (eg BHQ1) and a reporter (eg FAM) can be used.
- a reporter for example, a molecular beacon with self-quenching properties can be used. The signal is generated only when a complementary bond. This allows, for example, complete P1-text to be distinguished from incomplete ones.
- the synthesis phase and the controlling phase may take place simultaneously, as illustrated by the reaction approach illustrated in FIG. Controller and primer as well as their complex are in equilibrium during the reaction ( Figure 6 A)).
- the synthesis of the primer extension product is initiated by the addition of a polymerase.
- the polymerase can start the synthesis of a complementary primer extension product ( Figure 6B)).
- the polymerase-catalyzed synthesis of fully complementary products occurs faster than the synthesis of products that involve a mismatch due to an error arising during the synthesis.
- the mismatch strands are synthesized more slowly.
- Fig. 7 and 8 further schematic representations of a reaction mixture with simultaneous synthesis phase and controlling phase are shown. Controller and primer as well as their complex are in equilibrium during the reaction before (Fig. 7 A), Fig. 8 B)).
- the free-of-charge controllers can interact with the primer extension products during the synthesis phase. The interaction starts at the second primer area of a respective primer extension product ( Figure 7B), Figure 8B)).
- the result of the controller's interaction with the primer extension products will be different depending on the progress of the synthesis of the primer extension product: with fully synthesized P1-Ext, this product may be released.
- a fully synthesized P1 -ex can interact through its 3 ' segment with other oligonucleotides, eg probes, primers etc.
- Figures 9A-C schematically show the topography of a template strand (comprising a target sequence) with a polymorphic locus (N2) and two unitary target sequence segments (N1 and N3).
- the template strand with the first variant (M 1.1) and the template strand with the second variant (M 1 .2) schematically show the topography of a target sequence within template strands.
- Both template strands comprise target sequence segments N1 and N3, which are identical and uniform in both template strands.
- the respective sequence segment N2 is characteristic and specific in each template strand, so that both template streaks can be distinguished by it.
- N2 comprises at least two sequence variants of a polymorphic locus of a target sequence.
- M 1 .1 template with the first variant of the target sequence.
- M 1.2 template with the second variant of the target sequence.
- N1 first unified target sequence segment in which S1.1 is identical to S1 .2.
- N2 polymorphic locus, in which S1.1 is not identical to S1.2.
- N3 second uniform target sequence segment, in which S1 .1 is identical to S1 .2.
- B1.1 block oligonucleotide for limiting a primer extension.
- a target sequence which may comprise a plurality of sequence variants in a polymorphic locus (N2), furthermore comprises at least a first target sequence segment (N1) which is suitable for all target sequence variants of a target sequence (target sequence group comprising M 1 .1 and M 1 .2 ) is characteristic and uniform.
- a target sequence comprises at least one second target sequence segment (N3) which is characteristic and uniform for all target sequence variants of a target sequence (target sequence group comprising M 1 .1 and M 1 .2 here).
- Such uniform target sequence segments are preferably located on either side of a polymorphic locus and thus flank a polymorphic locus (with sequence variants) of a target sequence from both sides.
- the first uniform target sequence segment (N1) differs in its sequence composition from the Sequence composition of the second unitary target sequence segment (N3) in at least one nucleotide position.
- Figures 10 show schematically the topography of a template strand with a polymorphic locus (N2) and two unitary target sequence segments (N1 and N3) as shown in Figure 9.
- Figure 10D shows the result of strand separation after primer extension by two specific and unique controller oligonucleotides (C1.1 and C1 .2), each of which controller oligonucleotides provides a polymorphic locus of the target sequence (N2) corresponding sequence segment, wherein C1 .1 and C1 .2 differ in this sequence segment.
- both primer extension products formed during synthesis both comprise fully-complementary sequences. Binding of such fully complementary sequences to each other is more effective than in sequences involving a mismatch. The strand separation thus runs only over a shorter distance and is less effective than with fully complementary strands.
- Fig. 11 schematically shows another topography of an N2 of a target nucleic acid chain with respect to the controller oligonucleotide and the first primer.
- the N2-corresponding sequence segment of the controller oligonucleotide partially comprises the third region as well as partially the second region.
- the 3 ' segment of the first primer is designed to be sequence specific and characteristic of a specific and characteristic sequence variant of the target nucleic acid.
- both the controller oligonucleotide and the first primer oligonucleotide participate in allele discrimination.
- both a specific controller oligonucleotide and a specific first primer oligonucleotide can be constructed.
- Figure 12 shows schematically potential positions of a polymorphic locus within a target sequence (positions 1 to 6) and their corresponding sequence segment positions in the individual components of a primer extension system.
- the polymorphic loci of a target sequence shown schematically comprise 2 to 50 nucleotides, in particular 4 to 30 nucleotides, which are characteristic and specific for an allelic variant of a target sequence.
- the arrangement of individual amplification components can be designed so that several variants / combinations are possible:
- Arrangement 1 A polymorphic locus (N2) of the target sequence overlays the first primer (in the first region) and the controller oligonucleotide (in the second region).
- Sequence variate of the target sequence can be constructed.
- Array 2 A polymorphic locus (N2) of the target sequence overlays the first primer (in the first region) and the controller oligonucleotide (in the second region).
- Sequence variate of the target sequence can be constructed.
- Arrangement P2 differs from P1 mainly in that N2 lies predominantly in the 3 ' terminal sequence segment of the first primer. As a result, if necessary, a better specificity of the amplification can be achieved.
- Arrangement 3 A polymorphic locus (N2) of the target sequence overlays only the controller oligonucleotide (in the third region) with the corresponding sequence segment of the controller oligonucleotide in the 5 ' segment of the synthesized portion of the first primer extension product.
- the controller oligonucleotide of the amplification system can thus be constructed specifically and characteristically for the respective sequence variant of the target sequence.
- a target sequence specific first primer is used, which is not sequence variant specific. Because of the possible proximity of the second blocking moiety, the binding of the controller oligonucleotides to the first primer extension product can be affected by nucleotide modifications of the second blocking moiety.
- Arrangement 4 (P4-P6): A polymorphic locus (N2) of the target sequence overlays only the controller oligonucleotide (in the third region).
- the controller oligonucleotide of the amplification system can thus be constructed specifically and characteristically for the respective sequence variant of the target sequence.
- a target sequence specific first primer is used, but which are not sequence variant specific.
- This sequence segment of the controller oligonucleotide lies in the 5 ' direction from the second blocking unit and may comprise several DNA nucleotide monomers, eg from 5 to 30.
- Figures 13-14 show schematically the topography of a target nucleic acid chain with a polymorphic locus (N2) and two unitary target sequence segments (N1 and N3), where the polymorphic locus comprises only one nucleotide position (eg an SNV or an SNP or a point mutation Etc.).
- the differences between individual sequence variants thus amount to only one nucleotide (here referred to as 4.1 and 4.2).
- Such a locus (N2) can lead to similar arrangements of individual components as a locus with at least 2 nukeotids.
- the controller oligonucleotide is bound to a complementary first primer extension product (perfect match), strand separation following a primer can thus be achieved. Extension done. In the formation of a mismatch strand separation is inhibited or slowed down or even interrupted.
- Fig. 15 shows schematically potential positions of a polymorphic locus with sequence variance of only one nucleotide within a target sequence (positions 1 to 6) of a template strand and their corresponding sequence segment positions in individual components of a primer extension system.
- Arrangement 1 A polymorphic locus (N2) of the target sequence overlays the first primer (in the first region) and the controller oligonucleotide (in the second region).
- Sequence variate of the target sequence can be constructed.
- Array 2 A polymorphic locus (N2) of the target sequence overlays the first primer (in the first region) and the controller oligonucleotide (in the second region).
- Sequence variate of the target sequence can be constructed.
- Arrangement P2 differs from P1 primarily in that N2 may be predominantly in the 3 ' terminal sequence segment of the first primer or even comprises the 3 ' terminal nucleotide. This may possibly result in a further increase in the specificity of the amplification.
- Arrangement 3 A polymorphic locus (N2) of the target sequence overlays only the controller oligonucleotide (in the third region) with the corresponding sequence segment of the controller oligonucleotide in the 5 ' segment of the synthesized portion of the first primer extension product.
- the controller oligonucleotide of the amplification system can thus be constructed specifically and characteristically for the respective sequence variant of the target sequence.
- a target sequence specific first primer is used, but which are not sequence variant specific. Because of the possible proximity of the second blocking moiety, the binding of the controller oligonucleotides to the first primer extension product can be affected by nucleotide modifications of the second blocking moiety.
- Arrangement 4 (P4-P6): A polymorphic locus (N2) of the target sequence overlays only the controller oligonucleotide (in the third region).
- the controller oligonucleotide of the amplification system can thus be constructed specifically and characteristically for the respective sequence variant of the target sequence.
- a target sequence specific first primer is used, which is not sequence variant specific.
- This sequence segment of the controller oligonucleotide lies in the 5 ' direction of the second blocking unit.
- This segment of the controller oligonucleotide may comprise multiple DNA nucleotide monomers, eg from 5 to 30, wherein the N2-corresponding sequence segment may be flanked by at least 3 to 15 DNA nucleotide building blocks on both sides.
- a specific P1 .1 may preferably bind specifically to the complementary position of a specific sequence variant of the template strand (S1.1) under reaction conditions and initiate the synthesis of the P1.1 -ext. No competitor primer is used.
- P1 .1 -Ext can bind complementarily to C1 .1 and be released from the template strand with its participation.
- a specific P1 .1 can preferentially bind specifically to the complementary position of a specific sequence variant of the template strand (M 1 .1) under reaction conditions and initiate the synthesis of the P1.1 -ext.
- M 1 .1 a specific sequence variant of the template strand
- P1.1-Ext. No competitor primer is used.
- the binding to another sequence variant (M 1 .2) is less efficient due to the mismatch with position (N) within the primer binding site of M 1 .2.
- the primer extension is thus started less efficiently under stringent reaction conditions.
- Fig. 18 shows schematically an embodiment with topography of a specific primer extension system and a polymorphic locus (N2) template strand in certain embodiments in which the segment of the controller oligonucleotide corresponding to N2 lies in the second region (2).
- the N2 locus includes the 3 '- terminal nucleotide of the first primer.
- a specific P1.1 with a complementary 3 '- terminal nucleotide under the reaction conditions can preferably specifically bind to the complementary position of a specific sequence variant of the template strand (M 1 .1) bind and initiate synthesis of P1 .1-Ext.
- M 1 .1 specific sequence variant of the template strand
- No competitor primer is used.
- the binding to another sequence variant (SN 1 .2) is less efficient due to the mismatch with position (N) within the primer binding site of M 1.2.
- the primer extension is thus started less efficiently under stringent reaction conditions.
- Fig. 19 shows schematically an embodiment with topography of a specific primer extension system and a polymorphic locus (N2) template strand in certain embodiments in which the segment of the controller oligonucleotide corresponding to N2 lies in the third region (Fig. 3).
- Target sequence specific but not sequence variant specific first primers are used.
- One for all sequence variants of one Target nucleic acid unitary P1 .1 can bind to the template strand and initiate the synthesis of the P1 1 -ext.
- P1 .1-Ext is formed.
- No competitor primer is used.
- the separation of primer extension products P1.1 -Ext from the template strand is preferably carried out specifically by complementary binding of P1.1 -Ext to the controller oligonucleotide.
- the separation of strands of another sequence variant synthesized using (M 1.2) is less efficient due to the mismatch with position (N) to the corresponding sequence segment of the controller oligonucleotide.
- the position of the sequence segment (3) corresponding to N2 of the target sequence is in the vicinity of the second blocking unit, so that the interaction between the controller oligonucleotide and the respective first primer extension product are affected by modifications used in the second blocking unit can.
- Fig. 20 shows schematically an embodiment with topography of a specific primer extension system and a polymorphic locus (N2) template strand in certain embodiments, in which the N2-corresponding segment of the controller oligonucleotide lies in the third region (4).
- Target sequence specific but not sequence variant specific first primers are used.
- a P1.1 unitary for all sequence variants of a target nucleic acid can bind to the template strands and initiate the synthesis of the P1 1 -text. In the course of primer extension, this results in the formation of P1 1- Ext. No competitor primer is used.
- the separation of primer extension products P1.1 -Ext from the template strand is preferably carried out specifically by complementary binding of P1.1 -Ext to the controller oligonucleotide.
- the separation of strands of another sequence variant synthesized using (M 1.2) is less efficient due to the mismatch with position (N) to the corresponding sequence segment of the controller oligonucleotide.
- the position of the sequence segment (4) corresponding to N2 of the target sequence is at a distance from the second blocking moiety, so that the interaction between the controller oligonucleotide and the respective first primer extension product of modifications used in the second blocking moiety in FIG Essentially unaffected.
- the segment of the controller oligonucleotide corresponding to N2 is preferably made up of DNA monomers using between 4 to 20 DNA monomers and at least 4 to 10 DNA monomers located around position-4 on both sides.
- Fig. 21 shows schematically an embodiment with topography of a specific primer extension system and a polymorphic locus (N2) template strand in certain embodiments in which the N2-corresponding segment of the controller oligonucleotide lies in the second region.
- a specific P1 .1 may preferably bind specifically to the complementary position of a specific sequence variant of the template strand (M 1 .1) under reaction conditions and initiate the synthesis of the P1.1 -ext. In the course of primer extension, this leads to the formation of P1 1-Ext.
- the binding to another sequence variant (M 1 .2) is less efficient due to the mismatch with position (N) within the primer binding site of M 1.2.
- the primer extension is thus started less efficiently under stringent conditions.
- the P5.1 forms a perfect match with M 1 .2 and can be extended by the polymerase to form a competitor primer extension product P5.1-Ext.
- Figure 21 shows variants of competitor primer P5.1 for P1 .1 with no overhang for binding to the controller oligonucleotide, with the 3 ' end of P5.1 binding within the second blocking unit.
- a competitor primer oligonucleotide (P 5.1) is added to the reaction which is capable of binding predominantly complementarily to the sequence variants of the target sequence and whose copy formation with subsequent separation from the template strand is suppressed must become. Due to a complementary binding with such primer binding sites, a competitor primer may preferentially bind and be extended by the polymerase. The resulting product (here P5.1 -Ext) blocks the single-stranded primer binding sites for an interaction of the first primer.
- the 3 ' end of a competitor primer binds within the second blocking unit of the controller oligonucleotide so that extension of this primer on the controller oligonucleotide can not occur.
- the competitor primer does not include a sequence segment that can interact with the first region of the controller oligonucleotide. This prevents the extension product of the competitor oligonucleotide from being detached from the template.
- FIG. 22 schematically shows an embodiment with topography of a specific primer extension system and a polymorphic locus (N2) template strand in certain embodiments in which the N2-corresponding segment of the controller oligonucleotide lies in the second region (FIG. 2).
- the N2 locus includes the 3 '- terminal nucleotide of the first primer.
- a specific P1 .1 having a complementary 3 ' -terminal nucleotide can preferably bind specifically to the complementary position of a specific sequence variant of the template strand (M 1 .1) under reaction conditions and initiate the synthesis of the P1 1 -text.
- P1 .1-Ext P1 .1-Ext.
- the binding to another sequence variant (M 1 .2) is less efficient due to the mismatch with position (N) within the primer binding site of SN 1.2.
- the primer extension is thus started less efficiently under stringent conditions.
- a competitor primer (P5.2) is added to the reaction which is capable of binding predominantly complementarily to the sequence variants of the target sequence and whose primer extension and subsequent separation from the template strand must be suppressed , Due to a complementary binding with such primer binding sites, a competitor primer can preferably bind to particular sequence variants (designated here by N) and extended by the polymerase.
- the resulting product (P5.2-Ext) blocks the single-stranded primer binding sites for interaction with the first primer.
- the 3 ' end of a competitor primer binds within the second blocking unit of the controller oligonucleotide so that extension of this primer on the controller oligonucleotide can not occur.
- the competitor primer does not include a sequence segment with which it can interact with the first region of the controller oligonucleotide. This prevents the extension product of the competitor oligonucleotide from being detached from the template.
- Figure 22 shows variants of competitor primer 5.2 for P1.1 with no overhang for binding to the controller oligonucleotide, with the 3 ' end of P5.2 binding within the second blocking unit.
- the 3 ' -terminal segment of P5.2 forms a perfect match with M 1.2 and can be extended by the polymerase.
- FIG. 23 schematically shows an embodiment with topography of a specific primer extension system and a polymorphic locus (N2) template strand in certain embodiments in which the N2-corresponding segment of the controller oligonucleotide lies in the third region (FIG. 3).
- Target sequence specific but not sequence variant specific first primers are used.
- a P1 .1 unitary to all sequence variants of a target nucleic acid can bind to the template strands and initiate the synthesis of P1.1-Ext.
- P1 .1-Ext During primer extension, P1 .1-Ext.
- the separation of synthesized primer extension products P1.1 -Ext from the template strand is preferably carried out specifically by complementary binding of P1 .1-Ext to the controller oligonucleotide.
- the separation of strands of another sequence variant synthesized using (M 1.2) is less efficient due to the mismatch with position (N) to the corresponding sequence segment of the controller oligonucleotide.
- the position of the sequence segment (3) corresponding to N2 of the target sequence is in the vicinity of the second blocking unit, so that the interaction between the controller oligonucleotide and the respective first primer extension product are affected by modifications used in the second blocking unit can.
- a competitor primer P5.3 is added to the reaction which is able to bind predominantly complementarily to the sequence variants of the target sequence (N) and whose copy generation and subsequent strand separation must be suppressed. Due to a complementary binding with such primer binding sites, a competitor primer may preferentially bind to certain sequence variants (designated here by N) and be extended by the polymerase. The resulting product blocks the single-stranded primer binding sites for interaction with the first primer.
- the competitor primer oligonucleotide (P5.3) is longer than the first primer oligonucleotide such that its 3 ' end is within the fourth blocking moiety of the Controller oligonucleotide can bind (the fourth blocking unit is assembled analogously to the second blocking unit and blocks a primer extension on the controller oligonucleotide), so that no extension of this primer can be done on the controller oligonucleotide.
- the competitor primer does not include a sequence segment which can interact with the first region of the controller oligonucleotide. This prevents the extension product of the competitor oligonucleotide from being detached from the template.
- Figure 23 shows variants of competitor primer 5.3 for P1.1 with no overhang for binding to the controller oligonucleotide, with the 3 ' end of P5.3 binding within the fourth blocking unit.
- the 3 ' -terminal segment of P5.3 forms a perfect match with M 1.2 and can be extended by the polymerase.
- Figure 24 shows schematically a selective primer extension reaction of several sequence variants using multiple selective controller oligonucleotides (C1.1 and C1.2).
- Figures 25-29 show schematically the structure of the first primer oligonucleotide and the controller oligonucleotide, as well as the interaction between the first primer oligonucleotide and the template, as well as the synthesis of the first primer extension product.
- Figure 30 shows schematically the interaction between structures during primer extension of the first primer oligonucleotide.
- Fig. 33 shows schematically some embodiments of structures of a starting nucleic acid chain and their use as template at the beginning of the reaction. Using P1.1, without block oligonucleotide.
- Fig. 34 shows schematically some embodiments of structures of a starting nucleic acid chain and their use as a template at the beginning of the reaction. Using P1.1, with block oligonucleotide.
- FIG. 35 shows schematically the interaction of the structures during the nucleic acid amplification by, on the one hand, the amplification of the first primer oligonucleotide and of the second primer oligonucleotide and furthermore the action of the controller oligonucleotide and the resulting strand displacement.
- FIGS. 36-38 show results from Example 4.
- Fig. 39 shows schematically an embodiment with topography of a specific primer extension system and a template strand with a polymorphic locus (N2) in certain embodiments, in addition to other illustrations the following nomenclature of reaction components and sequence segments is used: a) a sample comprising a nucleic acid polymer comprising the target sequence M, wherein the target sequence in 5'-3 'orientation comprises the sequence sections MS and MP and MP is located directly in 3' of MS, with the following
- an oligonucleotide primer P which comprises the sequence sections PC and PM in the 5'-3 'orientation and PM is arranged directly in 3' of PC, wherein PM has the sequence [MPa] complementary to the sequence section MP [that binds] in a substantially sequence-specific manner can] and PC can not bind to M [or a sequence immediately adjacent to MP in 3 '];
- Sequence sections CS, CP and CC where CP is located immediately in the 3 'direction of CS and immediately in the 5' direction of CC, and where CS is at least to the 3 ' segment of MS (immediately in the 5' direction of MP lying) and CP and CC to the sequence section PM and PC
- CS comprises modified nucleotide building blocks such that CS can not serve as a template for the activity of the template-dependent nucleic acid polymerase;
- a template-dependent nucleic acid polymerase in particular a DNA polymerase, as well as substrates of the DNA polymerase (in particular ribonucleoside triphosphates or deoxyribonucleoside triphosphates) and suitable cofactors, a primer extension product P 'being obtained which, besides the
- Sequence areas PC and PM comprises a synthesized area PS, which is substantially complementary to the target sequence MS,
- reaction conditions are chosen, and / or
- the lengths and the melting temperature of PC and possibly MS are selected so that P 'can form a double strand with M and P' can form a double strand with C and the formation of the double strand from P 'and C opposite the formation of the double strand from P 'is preferred with M.
- Sequence section CS 'of 5 to 15 nucleotide positions contains length, which consists of nucleic acid analogs, in particular of 2'0-alkyl ribonucleotides.
- M comprises a sequence portion MB immediately in 5 'of MS, and further wherein a block oligonucleotide B capable of hybridizing to MB is contacted with the sample, and wherein a.
- B comprises nucleoside analogs selected such that a B hybrid to MB does not permit the MB-dependent nucleic acid polymerase reaction on MB or
- the template-dependent nucleic acid polymerase is selected such that a
- a nucleic acid polymer (one embodiment of the template) comprises the target sequence M, which comprises the sequence segments MS and MP and MP in the 5'-3 'orientation and is located directly in 3' of MS.
- the target sequence comprises a polymorphic locus (N2).
- An oligonucleotide primer P (corresponding to a first primer oligonucleotide) comprises, in 5'-3 'orientation, the sequence segments PC (corresponding to a second region of the first primer oligonucleotide) and PM (corresponding to a first region of the first primer oligonucleotide).
- a controller oligonucleotide C comprises, in 5'-3 'orientation, the sequence sections CS (corresponding to a third region of the controller oligonucleotide), CP (corresponding to a second region of the controller oligonucleotide) and CC (corresponding to a first region of the controller oligonucleotide )
- a primer extension product P ' (corresponding to a first primer extension product) is obtained by template-dependent extension of the first primer oligonucleotide.
- the primer extension product comprises a synthesized region PS which is essentially complementary to the target sequence MS
- a variant VM of the target sequence M is different from the sequence M in at least one position VMM.
- this position has one or more substitution (s), insertion (s) and / or deletion (s).
- This position VMM in this embodiment is a sequence variant of the polymorphic locus (N2) of the target sequence.
- VMM is at the 5 'end of VMP. in other words, the 3 'end of VPM hybridizes with VMM.
- a second controller oligonucleotide VC comprises in the 5'-3 'orientation the sequence sections VCS (corresponding to a third area of the controller oligonucleotide), VCP (corresponding to a second area of the controller oligonucleotide) and VCC (corresponding to a first area of the controller). oligonucleotide).
- a second oligonucleotide primer VP (corresponding to a variant of a first primer oligonucleotide) comprises, in the 5'-3 'orientation, the sequence segments VPC (corresponding to a second region of the first primer oligonucleotide) and VPM (corresponds to a first region the first primer oligonucleotide) and VPM is located immediately in 3 'of VPC, where VPM has [the hybridizing] sequence complementary to the sequence portion VMP of the target sequence VM and can not bind VPC to VM [or one in 3 'immediately following VMP sequence] can bind.
- VMM polymorphic locus N2 of the target sequence resides at the 5 'end of VMP and the 3' end of VPM (of the first primer oligonucleotide) can be specifically hybridized with VMM.
- a competitor oligonucleotide KP can hybridize to the target sequence.
- KP can hybridize with VMP of the target sequence.
- a block oligonucleotide B can hybridize to a sequence portion of the target sequence MB immediately adjacent to the 5 'direction of MS, where B comprises nucleoside analogs selected such that a hybrid (complex) of B with MB is the response of a template-dependent one Nucleic acid polymerase not allowed on MB.
- Figures 40-58 schematically show certain embodiments for using a primer extension product as a starting nucleic acid chain for an amplification method.
- P5.1 does not contain an overhang for binding to the activator oligonucleotide.
- P5.1 has the same length as the first range of P1 .1
- FIG. 53 shows variants of competitor primer P 5.2 for P1 .1:
- P5.2 does not contain an overhang for binding to the activator oligonucleotide.
- P5.2 has a longer binding segment at SN 1 .2 than the first region of P1.1
- FIG. 54 shows variants of competitor primer P 5.3 or P5.4 for P1 .1:
- Figures 59-60 schematically show certain topographical embodiments of a specific primer extension system and a polymorphic locus (N2) template strand in certain embodiments, in addition to other illustrations, the following are Nomenclature of reaction components and sequence segments used (see nomenclature Fig. 39).
- P3.1-Ext part 1 extension product of P3.1 synthesized on P2.1 -EX as template.
- P4.1 Ext Part 1 Extension product of P4.1 synthesized on P1.1 -xt as template.
- P3.1-Ext extension product of P3.1 synthesized using P4.1 -Ext part 1 or at the P4.1 -Ext as template.
- P4.1 -Ext extension product of P4.1 synthesized using P3.1 Ext part 1 or at the P3.1 text as template.
- Potassium glutamate 50 mmol / l, pH 8.0; Magnesium acetate, 10 mmol / l; dNTP (dATP, dCTP, dTTP, dGTP), 200 pmol / l each; Polymerase (Bst 2.0 warm start, 120,000 U / ml NEB), 12 units / 10 pl;
- Triton X-100 0.1% (v / v); EDTA, 0.1 mmol / l; TPAC (tetrapropylammonium chloride), 50 mmol / l, pH 8.0; EvaGreen dye (dye was according to manufacturer's instructions in
- 1x isothermal buffer (New England Biolabs); in simple concentration, the buffer contains: 20 mM Tris-HCl; 10mM (NH 4 ) 2 S0 4 ; 50 mM KCl; 2mM MgSO 4 ; 0.1% Tween® 20; pH 8.8@25 ° C); dNTP (dATP, dCTP, dUTP, dGTP), 200 pmol / l each;
- the melting temperature (Tm) of the components involved was determined at concentration of 1 pmol / l of respective components in solution 1 or 2. Different parameters are indicated in each case.
- Primer extension reactions and amplification were performed by default at two reaction temperatures of 55 ° C and / or 65 ° C. Deviations are indicated.
- the start of the reaction was carried out by heating the reaction solutions to reaction temperature, since Bst 2.0 polymerase warm start at lower temperatures is largely inhibited in their function by a temperature-sensitive oligonucleotide (an "aptamer” according to the manufacturer).
- the polymerase becomes increasingly more active from a temperature of about 45 ° C, at a temperature of 65 ° C, no differences between Polymerase Bst 2.0 and Bst 2.0 warm start were found.
- Polymerase Bst 2.0 Warmstart was used. Deviations are specified.
- the reaction was stopped by heating the reaction solution to above 80 ° C, e.g. 10 min at 95 ° C. At this temperature, the polymerase Bst 2.0 is irreversibly denatured and the result of the synthesis reaction can not be subsequently changed.
- reactions were carried out in a thermostat with a fluorescence measuring device.
- a commercial real-time PCR device was used, StepOne Plus (Applied Biosystems, Thermofischer).
- the reaction volume was 10 pl by default. Deviations are indicated.
- endpoint determinations the signal was registered by nucleic acids bound to nucleic acids, e.g. TMR (tetramethyl-rhodamine, also called TAMRA) or FAM (fluorescein).
- TMR tetramethyl-rhodamine
- FAM fluorescein
- the wavelengths for excitation and measurement of the fluorescence signals of FAM and TMR are stored as factory settings in the StepOne Plus Real-Time PCR device.
- an intercalating dye (EvaGreen) was used in end point measurements, e.g. when measuring a melting curve).
- EvaGreen is an intercalating dye and is an analog of the commonly used dye Sybrgreen, but with slightly less inhibition of polymerases.
- the wavelengths for excitation and measurement of the fluorescence signals of SybrGreen and EvaGreen are identical and are stored as factory settings in the StepOne Plus Real-Time PCR device. Fluorescence can be monitored continuously by means of built-in detectors, i. "online” or “real-time” are detected. Since the polymerase synthesizes a double strand during its synthesis, this technique could be used for kinetic measurements (real-time monitoring) of the reaction. Due to some cross-talk between color channels in the StepOne Plus device, partially increased basal signal intensity was observed in measurements where e.g. TMR-labeled primers in concentrations greater than 1 pmol / L (e.g., 10 pmol / L) were used. It has been observed that the TMR signal in the SybrGreen channel leads to increased baselines. These increased baseline values were taken into account in calculations.
Abstract
Description
Claims
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP18158720 | 2018-02-26 | ||
DE102018001639.1A DE102018001639A1 (de) | 2018-02-28 | 2018-02-28 | Verfahren zur Primer-Verlängerungsreaktion mit verbesserter Spezifität |
EP18195189.8A EP3530753A1 (de) | 2018-02-26 | 2018-09-18 | Verfahren zur primer-verlängerungsreaktion mit verbesserter spezifität |
PCT/EP2019/054755 WO2019162529A1 (de) | 2018-02-26 | 2019-02-26 | Verfahren zur primer-verlängerungsreaktion mit verbesserter spezifität |
Publications (1)
Publication Number | Publication Date |
---|---|
EP3759247A1 true EP3759247A1 (de) | 2021-01-06 |
Family
ID=67687059
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19711506.6A Withdrawn EP3759247A1 (de) | 2018-02-26 | 2019-02-26 | Verfahren zur primer-verlängerungsreaktion mit verbesserter spezifität |
Country Status (3)
Country | Link |
---|---|
US (1) | US20210071243A1 (de) |
EP (1) | EP3759247A1 (de) |
WO (1) | WO2019162529A1 (de) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ES2764975T3 (es) | 2014-12-15 | 2020-06-05 | Cepheid | Amplificación de ácidos nucleicos en base exponencial mayor de 2 |
EP3874064A1 (de) | 2018-10-29 | 2021-09-08 | Cepheid | Exponentielle base-3-nukleinsäureamplifikation mit reduzierter amplifikationszeit unter verwendung verschachtelter überlappender primer |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040091923A1 (en) * | 1993-07-23 | 2004-05-13 | Bio-Rad Laboratories, Inc. | Linked linear amplification of nucleic acids |
US5882857A (en) * | 1995-06-07 | 1999-03-16 | Behringwerke Ag | Internal positive controls for nucleic acid amplification |
WO2002018616A1 (en) * | 2000-09-01 | 2002-03-07 | Hitachi Chemical Co., Ltd. | Adjusting the efficiency of nucleic acid template amplification by attenuated pcr with template-mimic oligonucleotides |
EP2207896B1 (de) * | 2007-10-04 | 2014-01-29 | Commonwealth Scientific and Industrial Research Organisation | Nukleinsäureamplifikation |
EP3144396B1 (de) * | 2010-10-27 | 2020-01-01 | President and Fellows of Harvard College | Verwendungen von toehold-hairpin-primern |
ES2764975T3 (es) * | 2014-12-15 | 2020-06-05 | Cepheid | Amplificación de ácidos nucleicos en base exponencial mayor de 2 |
-
2019
- 2019-02-26 WO PCT/EP2019/054755 patent/WO2019162529A1/de unknown
- 2019-02-26 EP EP19711506.6A patent/EP3759247A1/de not_active Withdrawn
- 2019-02-26 US US16/975,542 patent/US20210071243A1/en not_active Abandoned
Also Published As
Publication number | Publication date |
---|---|
WO2019162529A1 (de) | 2019-08-29 |
US20210071243A1 (en) | 2021-03-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP3504338B1 (de) | Verfahren zur amplifikation von nukleinsäuren und verwendung eines kits zu dessen durchführung | |
DE60116651T2 (de) | Methode zur amplifizierung und möglicher charakterisierung von nukleinsäuren | |
DE69432919T2 (de) | Verfahren für den Nachweis spezifischer Polynukleotiden | |
DE60121750T2 (de) | Hybridisierungsprobe und methode zum schnellen nachweis und zur schnellen unterscheidung von sequenzen | |
DE602006000944T2 (de) | Verfahren zur Genotypisierung durch Schmelztemperaturabhängigkeit | |
DE69829328T2 (de) | Strangverdrängungsamplifikation von RNA | |
DE60219199T2 (de) | Analyse und detektion von mehreren zielsequenzen unter verwendung von zirkulären proben | |
DE60025840T2 (de) | Methode zum nachweis von variationen oder polymorphismen | |
DD284053A5 (de) | Ein verfahren zur verstaerkung von nucleotiden sequenzen | |
EP2207896A1 (de) | Nukleinsäureamplifikation | |
EP3759247A1 (de) | Verfahren zur primer-verlängerungsreaktion mit verbesserter spezifität | |
DE10253966B4 (de) | Microarray-basiertes Verfahren zur Amplifikation und Detektion von Nukleinsäuren in einem kontinuierlichen Prozess | |
WO1996027680A1 (de) | Sequenzspezifischer nachweis von nukleinsäuren | |
EP3759252A1 (de) | Verfahren zur selektiven amplifikation von nukleinsäuren und kit zu dessen durchführung | |
WO2019166586A1 (de) | Verfahren zur amplifikation einer nukleinsäure mit verbesserter spezifität | |
EP3530755B1 (de) | Verfahren zum anzeigen des fortschrittes der amplifikation von nukleinsäuren und kit zu dessen durchführung | |
DE102018001639A1 (de) | Verfahren zur Primer-Verlängerungsreaktion mit verbesserter Spezifität | |
EP3759248A1 (de) | Agverfahren zur amplifikation einer nukleinsäure mit verbesserter spezifität | |
DE102018001586A1 (de) | Verfahren zur Detektion der Amplifikation einer Nukleinsäure mit verbesserter Spezifität | |
EP0745687A1 (de) | Verfahren zur spezifischen Vervielfältigung und zum Nachweis von DNA bzw. RNA | |
DE102005048503B4 (de) | Verfahren zur Steuerung der abschnittsweisen enzymatischen Nukleinsäurevervielfältigung über inkomplette Komplementärstränge | |
EP0736608A1 (de) | Verfahren zur spezifischen Vervielfältigung und zum Nachweis von DNA bzw. RNA | |
EP3530753A1 (de) | Verfahren zur primer-verlängerungsreaktion mit verbesserter spezifität | |
EP0736609A2 (de) | Verfahren zur spezifischen Vervielfältigung und zum Nachweis von DNA bzw. RNA |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: UNKNOWN |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20200916 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
DAV | Request for validation of the european patent (deleted) | ||
DAX | Request for extension of the european patent (deleted) | ||
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20230901 |