CA2255851A1 - Process to eliminate haemoglobin errors when analysing medical samples - Google Patents

Process to eliminate haemoglobin errors when analysing medical samples Download PDF

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CA2255851A1
CA2255851A1 CA002255851A CA2255851A CA2255851A1 CA 2255851 A1 CA2255851 A1 CA 2255851A1 CA 002255851 A CA002255851 A CA 002255851A CA 2255851 A CA2255851 A CA 2255851A CA 2255851 A1 CA2255851 A1 CA 2255851A1
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haemoglobin
mmol
determination
sample
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French (fr)
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Ralph Weisheit
Elke Pfitschler
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Roche Diagnostics GmbH
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/72—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving blood pigments, e.g. haemoglobin, bilirubin or other porphyrins; involving occult blood
    • G01N33/721—Haemoglobin
    • 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
    • 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
    • C12Q1/26—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving oxidoreductase
    • C12Q1/32—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving oxidoreductase involving dehydrogenase
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/52—Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/70—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving creatine or creatinine

Abstract

The present invention relates to a process for determining an analyte in a sample containing free haemoglobin by optical bichromatic measurement for a main and a secondary measuring wave length. A secondary measuring wave length of above 475 nm is used containing absorption bands of haemoglobin.

Description

CA 022~8~1 1998-11-19 Nethod for the elimination of haemoglobin interferences in the analysis of medical samples Description The invention concerns a method for the determination of an analyte in a sample containing free haemoglobin in which the determination is carried out by an optical bichromatic measurement at a main and a secondary wave-length. In particular this method is suitable for the determination of the parameters ammonia, creatine kinase and isoenzymes thereof and lactate dehydrogenase and isoenzymes thereof in a medical sample e.g. a serum or plasma sample.

It is generally known that haemolysis interferes with the determination of many analytes in some cases to a considerable extent. In order to nevertheless obtain measured values which are unfalsified various methods have been published in the past for eliminating haemolysis interference.

One of these methods is that when measuring in automated analyzers a second wavelength (secondary wavelength) is used in addition to the first wavelength (primary wavelength) by means of which the interfering influence of interfering substances such as haemoglobin, bilirubin and lipaemia can be eliminated or at least minimized.

One requirement for this is that the substance to be measured absorbs as little as possible at the secondary wavelength but that the interfering substance absorbs at the same level as possible as at the main wavelength CA 022~8~l l998-ll-l9 ("Praxistechnik: Photometer fur die Arztliche Praxis, Deutscher Arzteverlag" 1977, pages 41-42).

In the DIA letter (Boehringer Mannheim) No. 70 (1985) it is mentioned that the secondary wavelength should be as close as possible to the main wavelength since as a rule the interfering substance then has similar absorbances at the main and secondary wavelengths.

In Clin. Chem. 25/6, 951-959 (1979) it is pointed out that the secondary wavelength should be selected so that it is near to the absorption minimum of the chromogen and near to the absorption maximum of the interfering substance. In this connection a secondary wavelength of 380 nm is recommended for the determination of glucose (main wavelength 340 nm) since here the absorbance of the interfering substances is similar to that at 340 nm.

In contrast in the Eur. J. Clin. Chem. Clin. Biochem.
31/9, 595-601 (1993) it is regarded as critical to measure W tests at a secondary wavelength of 380 nm since in this case the conversion of Hb-02 into Meth-Hb leads to spectral changes at 380 nm and thus to errors in the measurements. Therefore a secondary wavelength is recommended for tests which are based on the measurement of a decrease or increase in NAD(P)H which lies behind the so-called Soret region such as e.g. 475 nm.

All previously described methods relate to the elimination of interference in erroneous measurements caused by haemolysis. The availability of blood substitutes based on haemoglobin makes the issue of removing interferences by native or synthetic haemoglobin or compounds analogous to Hb much more acute .. .... . . ..

CA 022~8~1 1998-11-19 than hitherto. Such interferences then on the one hand also occur in non-haemolytic sample material and on the other hand also to a much greater extent than in native haemolysis since the haemoglobin content of blood serum or plasma can be up to 2000 mg/dl in blood substitute therapy.

In addition it was found that when measuring certain analytes such as ammonia, creatine kinase and isoenzymes thereof as well as lactate dehydrogenase and isoenzymes thereof it is not easily possible to achieve an adequate elimination of haemoglobin interference by using a secondary wavelength of 475 nm or higher e.g. at 480, 505, 600, 660 or 700 nm. Since these parameters are of essential importance in the context of cardiovascular and emergency diagnostics as well as for the diagnosis of patients treated with blood substitutes, the object of the present invention was to provide a simple method for eliminating interferences which are caused by native haemoglobin or by blood substitutes based on synthetic haemoglobin or compounds similar to haemoglobin, in particular when measuring the above-mentioned analytes.

The object of the invention is achieved by a method for the determination of an analyte in a sample containing free haemoglobin by optical bichromatic measurement at a main and a secondary wavelength wherein a secondary wavelength above 475 nm is used in which the absorption bands of haemoglobin are located.

Preferred secondary wavelengths for the method according to the invention are in the range of 546 + 10 nm, in particular 546 + 5 nm as well as in the range of 570 +
10 nm and in particular 570 + 5 nm. The wavelengths 546 CA 022~8~1 1998-11-19 and 570 nm are most preferred.

The selection of the wavelengths according to the invention as secondary wavelengths was surprising since the greatest interferences by haemoglobin are obtained at the secondary wavelength of 405 nm known from the state of the art (for example instrument settings for the Boehringer Mannheim/Hitachi 717-analyser according to the instructions of the kit insert for the reagent to determine creatine kinase, order No. 1 273 248, Boehringer Mannheim Diagnostica Catalogue 1997) at which haemoglobin also absorbs. Furthermore in the aforementioned publication Eur. J. Clin. Chem. Clin.
Biochem. it is pointed out that a secondary wavelength should be used to eliminate interference by haemoglobin which lies beyond the Soret region (the main absorption band of haemoglobin) so that it would at most have been obvious to use those wavelengths as a secondary wavelength where there are no absorption bands at all of haemoglobin.

The method for eliminating interference according to the invention is suitable for methods in which the analyte is determined by optical measurement in particular by optical measurement at a main wavelength in the W
range. The method is particularly preferably carried out for tests which are based on a measurement of the increase or decrease of the concentration of NADH or NADPH in the sample. In this case one preferably uses a main wavelength in the range of 340 + 10 nm.

The method according to the invention is suitable for the determination of any samples in which free haemoglobin is present. Examples of such samples are CA 022~8~1 1998-11-19 haemolytic serum or plasma samples or samples which contain a blood substitute. Examples of blood substitutes which fall under the term "free haemoglobin"
within the sense of the present invention are derivatized, polymerized, modified or cross-linked derivatives of haemoglobins in particular of human haemoglobin or bovine haemoglobin such as DCL
haemoglobin (diaspirin cross-linked haemoglobin) and recombinantly produced haemoglobin.

In a preferred embodiment of the method according to the invention the content of an analyte selected from the group comprising ammonia, creatine kinase and isoenzymes thereof and lactate dehydrogenase and isoenzymes thereof is determined.

The determination of ammonia by the method according to the invention is preferably carried out according to the enzymatic W method (Da Fonseca-Wollheim F., Z. Klin.
Chem. Klin. Biochem. 11 (1973) 421).

Creatine kinase (CK) is preferably determined according to the "optimized standard method" of the German Society for Clinical Chemistry (J. Clin. Chem. Clin. Biochem. 15 (1977), 249). The creatine kinase isoenzyme CK-MB is preferably determined by the immunological W method (Wurzburg U. et al., Klin. Wschr. 54 (1976), 357).

The determination of lactate dehydrogenase (LDH) or of the lactate dehydrogenase isoenzyme (HBDH) (1-hydroxy-butyrate dehydrogenase) is preferably carried out according to the "optimized standard method" of the German Society for Clinical Chemistry (Z. Klin. Chem.
Klin. Biochem. 8 (1970), 658 and 10 (1972), 182).

CA 022~8~1 1998-11-19 A serum or plasma sample is preferably used as the sample in the method according to the invention in particular a human serum or plasma sample.

A particular advantage of the method according to the invention is that it can be carried out in an automated analyzer such as a Boehringer Mannheim/Hitachi 704 or 717 analyzer. In such analyzers it is easily possible to set the particularly preferred secondary wavelengths of 546 or 570 nm.

The invention is further elucidated by the following examples.

General methods A solution containing haemoglobin was added to one portion of a serum pool such that a haemoglobin content of 2000 mg/dl was reached. Another equal portion of the serum pool was admixed with an equivalent amount of a NaCl solution (154 mmol/l). Both portions were subsequently mixed together in different ratios in such a way that a Hb concentration series of 11 samples was formed, whereby one sample contained no Hb and the highest sample contained 2000 mg/dl Hb.

CA 022~8~1 1998-11-19 Example Determination of ammonia The determination was carried out on a Boehringer Mannheim/Hitachi 717 analyzer. The following reagents were used:

Reagent 1: 150 mmol/l triethanolamine buffer, pH 8.6;
15 mmol/l a-ketoglutarate; 1.5 mmol/l ADP

~eagent 2: 150 mmol/l triethanolamine buffer; pH 8.5;
15 mmol/l a-ketoglutarate; 1.5 mmol/l ADP;
0.31 mmol/l NADPH; > 24 U/ml glutamate dehydrogenase (GLDH) The test procedure was as follows: 200 ~l reagent 1 and after 5 min 50 ~l reagent 2 were added to 20 ~l sample.
The analyte was determined after a period of a further 40 sec. A main wavelength of 340 nm and secondary wavelengths of 405 nm, 480 nm, 505 nm, 600 nm, 660 nm and 700 nm (comparison) as well as of 546 nm and 570 nm (invention) were used for the measurement.

The result of this determination is shown in table 1. It can be seen that when using the measurement wavelengths of 546 and 570 nm according to the invention a considerably improved recovery was achieved than with the other wavelengths.

CA 022~8~1 1998-11-19 ExamPle 2 Determination of creatinine kinase The determination was carried out on a Boehringer Mannheim/Hitachi 717 analyzer. The following reagents were used:

~eagent 1: 110 mmol/l imidazole buffer; pH 6.7;
20.5 mmol/l glucose; 2.05 mmol/l EDTA;
2.5 mmoltl ADP; 6.1 mmol/l AMP; 12 ~mol/l diadenosine pentaphosphate; 2.5 mmol/l NADP; 25 mmol/l N-acetylcysteine; > 3.1 U/ml hexokinase (HK); > 1.8 U/ml glucose-6-phosphate dehydrogenase (G6P-DH) ~eagent 2: 25 mmol/l imidazole buffer; pH 7.5;
20.5 mmol/l glucose; 2.05 mmol/l EDTA;
61 mmol/l Mg2+; 184 mmol/l creatine phosphate The test procedure was as follows: 250 ~l reagent 1 and after 5 min 50 ~l reagent 2 were added to 7 ~l sample.
The analyte was determined after a period of a further 2 min. A main wavelength of 340 nm and secondary wavelengths of 405 nm, 480 nm, 505 nm, 600 nm, 660 nm and 700 nm (comparison) as well as of 546 nm and 570 nm (invention) were used for the measurement.

The result of this determination is shown in table 2. It can be seen that when using the measurement wavelengths of 546 and 570 nm according to the invention a considerably improved recovery was achieved than with CA 022~8~1 1998-11-19 the other wavelengths.

ExamPle 3 Determination of the creatine kinase isoenzyme CK-MB

The determination was carried out on a Boehringer Mannheim/Hitachi 717 analyzer. The following reagents were used:

~eagent 1: 110 mmol/l imidazole buffer; pH 6.7;
21 mmol/l glucose; 11 mmol/l Mg2+;
2.1 mmol/l EDTA; 2.4 mmol/l ADP; 6.0 mmol/l AMP; 12 ~mol/l diadenosine pentaphosphate;
2.4 mmol/l NADP; 24 mmol/l N-acetyl cysteine; > 3.0 U/ml HK; > 1.8 U/ml G6P-DH;
antibody, inhibitory capacity towards CK-M
up to 2000 U/l.

~eagent 2: 110 mmol/l imidazole buffer; pH 6.7;
21 mmol/l glucose; 2.1 mmol/l EDTA;
11 mmol/l Mg2+; 186 mmol/l creatine phosphate The test procedure was as follows: 250 ~l reagent 1 and after 5 min 50 ~l reagent 2 were added to 12 ~l sample.
The analyte was determined after a period of a further 3 min. A main wavelength of 340 nm and secondary wavelengths of 405 nm, 480 nm, 505 nm, 600 nm, 660 nm and 700 nm (comparison) as well as of 546 nm and 570 nm (invention) were used for the measurement.

The result of this determination is shown in table 3. It CA 022~8~1 1998-11-19 can be seen that when using the measurement wavelengths of 546 and 570 nm according to the invention a considerably improved recovery was achieved than with the other wavelengths.

Example 4 Determination of lactate dehydrogenase The determination was carried out on a Boehringer Mannheim/Hitachi 717 analyzer. The following reagents were used:

Reagent 1: 68 mmol/l phosphate buffer; pH 7.5;
> 0.73 mmol/l pyruvate Reagent 2: > 1.1 mmol/l NADH

The test procedure was as follows: 250 ~l reagent 1 and after 5 min 50 ~l reagent 2 were added to 5 ~l sample.
The analyte was determined after a period of a further 60 sec. A main wavelength of 340 nm and secondary wavelengths of 405 nm, 480 nm, 505 nm, 600 nm, 660 nm and 700 nm (comparison) as well as of 546 nm and 570 nm (invention) were used for the measurement.

The result of this determination is shown in table 4. It can be seen that when using the measurement wavelengths of 546 and 570 nm according to the invention a considerably improved recovery was achieved than with the other wavelengths.

CA 022~8~1 1998-11-19 Example 5 Determination of the LDH isoenzyme HBDH

The determination was carried out on a Boehringer Mannheim/Hitachi 717 analyzer. The following reagents were used:

Reagent 1: 68 mmol/l phosphate buffer; pH 7.5;
3.7 mmol/l a-oxobutyrate Reagent 2: > 1.1 mmol/l NADH

The test procedure was as follows: 250 ~l reagent 1 and after 5 min 50 ~l reagent 2 were added to 5 ~l sample.
The analyte was determined after a period of a further 60 sec. A main wavelength of 340 nm and secondary wavelengths of 405 nm, 480 nm, 505 nm, 600 nm, 660 nm and 700 nm (comparison) as well as of 546 nm and 570 nm (invention) were used for the measurement.

The result of this determination is shown in table 5. It can be seen that when using the measurement wavelengths of 546 and 570 nm according to the invention a considerably improved recovery was achieved than with the other wavelengths.
.

Table 1 Sample Hb content Content:at: ~Content at Content:at Content at ¦ Content at Content at Content at Content at mgidll 405nm ~O~nm ~ 505~nm~ 546nm 570nm ~600nm~ 660~nm 700nm:
[~Ig/dl]~ g/dl]~ [llg/dl] ~ [llg/dl]~ [llg/dl] [llg/dl]: [llg/dll : [llg/dll:
7 1200 160 171 175 167 156 175 166 164 ~O
8 1400 159 177 177 166 155 177 171 170 n 9 1600 176 180 178 162 152 178 178 180 ~, Sample Hb content Recovery ~ : Recovery: : Recovery Recovery Recovery Recovery Recovery Recovery [mg/dl]~ 405~nm ~ 480 nm: ~505 nm 546 nm 570 nm 600 nm~ 660 nm: 700 nm~
r/~] ~ [%] 1%]~ [%] ~ [o/~] ~ [%] [%] ~ [%]

Table 2 Sample Hbcontent ::Contentat :~Goltentat Contentat Contentat :Contentat Contentat Contentat: :Content:at mg/dl] ~ 405nm~ 430nm ~ 505~nm~ 546nm ~ 570nm ~600nm~: : 660nm ~::700nm lU/I] ~lU/Il :~lU/Il ~[U/l~ U/ll : :lU/ll - :lU/ll lUII]

800 191 164 166 168 170 162 166 166 ~, 8 1400 205 163 163 170 174 160 165 164 ~n 9 1600 212 163 163 173 174 161 164 162 n Sample Hb conten t Recovery : Recovery Recovery ~ Recovery ~Recovery Recovery Recovery Recovery [mg/dll : 405rm: ~:~ 480nrn:505nm:: 546nm~: 570nm: 600nm ::~:660nm: :700nm :~ [% ~ 1%]~ : : [%] ~ :: [%1:~: [%] : [%] : : [%] ~ [%]
0 10~, 100 100 100 100 100 100 100 Table 3 Sample Hb content Content at C~o~ nl~at ~Content at Content~ at~ Content~at ~ Content at Content at ~Cootent at~
[mg/dIJ~ 405nm 480nm ~ 505nm 546nm ~ 570nm ~600nm ~660nm~ 700nm [U/I] ~ ~ [U/Il ~U/Il~ [U/Il ~ lU/Il ~ lU/Il ~ ~ [U/I~ [U/IJ
0 40.6 40.2 40.7 41.5 40.1 40.7 40.8 38.1 2 200 49.7 41.2 39.4 40.7 42.6 39.1 39.7 37.9 3 400 58.9 37.3 38.2 41.8 41.6 38.8 36.0 37.2 4 600 68.1 38.5 36.8 43.1 40.8 36.1 37.7 36.5 800 75.3 36.6 35.7 42.6 42.4 32.7 36.3 32.5 ~, 6 1000 82.4 34.9 35.4 44.1 43.4 30.8 32.6 36.5 D
7 1200 82.5 39.6 33.9 44.4 44.5 27.5 36.7 32.8 ~~
8 1400 95.0 35.5 34.5 44.8 43.0 26.1 33.4 33.9 ~n 9 1600 99.2 37.3 35.0 44.1 44.3 25.9 31.7 29.4 n 1800 98.9 33.9 29.8 46.7 42.9 24.8 27.1 29.4 11 2000 97.1 33.2 29.1 48.1 44.1 22.4 27.9 29.9 Sample Hb content Recovery Recovery Recovery ~ ~ Recovery Recovery Recovery Recovery Recovery [mg/dIJ 405 nm ~ ~ 480 nm 505 nm ~ 546 nm ~ ~ ~ 570 nm 600 nm 660 nm 700 nm riO]~ 1%] ~ 1%1 ~ ~ 1%1 ~ [%] lo/o] lo/O] ~ ~ ~1%]

Table 4 Samp!e Hb content Content at Content~:at~ Content at: Content at Content~at Content:at ~C~ntent~:at ~Content at:
mg/dl] 405 nm 480 nm 505::nm~ 546 nm ~570 nm 600 nm~ fo60:nm 700 nm [U/l]~ U/I]~ ~tU/I]~ [Uil]~ ~lU/I]~ [U/l] ~:~ [U/l]::: [U/l]

800 72 220 228 200 192 225 222 222 ~, q 1600 -13 230 238 199 190 242 233 236 Sample Hb content Recovery Recovery~ Recovery: ~Recovery Recovery Recovery Recovery:: Recovery [mg/dll: 405 rm :: 480 nm : ~505 nm 546 nm ~ :570 nm 600:nm 660 nm 700 nm ~ [% ~ 1%] ~ [%l~ [%] : [%l ~ [%] ~ [%] ~: : [%]
0 10~ 1 ~0 100 100 100 100 100 100 C C _ o ~ ~ ~ ~. ~ ~. ~ I'. o ~
_ ~0 ~ ~ ~ O ~ ~ ~ O O ~ o o ~) o ~) ~) ~ U) U') O N

c ~ o ~ ~ ~ r_ ~) o ~) ~ ~ N
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~D o ~ N ~ Ln ~ ~t o ~ ~ o N o O ~ ~ o o ~ ~ o ~ ~ ~ ~ N ~

~ :: ~:::::::
-- ~ S) N ~ ~) ~ tS) ~) ~) N
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~: ~: E :: : "
N~'O ~ 0 '-- O 0 ~ ~ ~ 0 ,o o O O C~ 0 0 0 ~ 0 o 0 0 ~) ~ ~) ~ N ~ ~ E ~
o~ o _ 8 0 0 0 0 o o o o o o o o o o o o o o o ~ ~ o ~

~c~ C~ _ O o N CD ~ ~t 0 0 ~ ~E ~:~
C ~ ~ 0 0 CJ~ o o o o o o o ~~ 0~ o c~ O O O O O O ~ o o ~ ~ _ ~

--O Ln u) O O CD ~- O ~) N 1~
N N ~ 0 ~ ~ 0 0 ~~ ~ If) ~ ~ N0 ~D ~) ~ ~ :
o ~ 0 0~ O O ~~ O N ~ ~ O ~D~ ~ ~ O ~~ ~ ~ ~ ~ ~ o Q
N ~ ~ ~ ~ ~ E ~ N

. . _ ~

Claims (12)

Claims
1. Method for the determination of an analyte in a sample containing free haemoglobin by optical bichromatic measurement at a main and secondary wavelength, wherein a secondary wavelength above 475 nm is used at which absorption bands of haemoglobin are located.
2. Method as claimed in claim 1, wherein a secondary wavelength in the range of 546 ~ 10 nm is used.
3. Method as claimed in claim 1, wherein a secondary wavelength in the range of 570 ~ 10 nm is used.
4. Method as claimed in one of the claims 1-3, wherein a test is carried out which is based on a measurement of the increase or decrease of the concentration of NADH or NADPH in the sample.
5. Method as claimed in claim 4, wherein a main wavelength in the range of 340 ~ 10 nm is used.
6. Method as claimed in one of the claims 1-5, wherein the content of an analyte is determined selected from the group comprising ammonia, creatine kinase and isoenzymes thereof and lactate dehydrogenase and isoenzymes thereof.
7. Method as claimed in claim 6, wherein ammonia is determined.
8. Method as claimed in claim 6, wherein creatine kinase or/and the creatine kinase isoenzyme CK-MB is determined.
9. Method as claimed in claim 6, wherein lactate dehydrogenase or/and the lactate dehydrogenase isoenzyme HBDH is determined.
10. Method as claimed in one of the claims 1-9, wherein a sample is determined which contains a blood substitute.
11. Method as claimed in one of the claims 1-10, wherein the determination is carried out on a serum or plasma sample.
12. Method as claimed in one of the claims 1-11, wherein the determination is carried out in an automated analyzer.
CA002255851A 1996-05-31 1997-05-30 Process to eliminate haemoglobin errors when analysing medical samples Abandoned CA2255851A1 (en)

Applications Claiming Priority (3)

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DE19622090.4 1996-05-31
DE19622090A DE19622090A1 (en) 1996-05-31 1996-05-31 Methods for eliminating hemoglobin disorders when analyzing medical samples
PCT/EP1997/002835 WO1997045733A1 (en) 1996-05-31 1997-05-30 Process to eliminate haemoglobin errors when analysing medical samples

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CA2255851A1 true CA2255851A1 (en) 1997-12-04

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DE19846301A1 (en) 1998-10-08 2000-04-13 Roche Diagnostics Gmbh Optical assay for determining alkaline phosphatase in samples uses specified primary and secondary measurement wavelengths
DE19846300A1 (en) 1998-10-08 2000-04-13 Roche Diagnostics Gmbh Optical assay for determining alkaline phosphatase in samples uses a specified primary measurement wavelength in combination with a rate blank correction
CN113502318A (en) * 2021-08-19 2021-10-15 东软威特曼生物科技(南京)有限公司 Creatine kinase isoenzyme CK-MB detection kit and detection method thereof

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WO1997045733A1 (en) 1997-12-04
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ATE198670T1 (en) 2001-01-15
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PL330220A1 (en) 1999-05-10
JPH11510902A (en) 1999-09-21
DE19622090A1 (en) 1997-12-04
EP0906570B1 (en) 2001-01-10
IL127275A0 (en) 1999-09-22
DE59702900D1 (en) 2001-02-15
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