Background technology
When organism infection pathogen, antigen is to occur one of infectious mark prior to antibody, the detection of antigen as a kind of pathogen, exist the most directly, the evidence of very early time and be applied to Serological testing, but because recall rate is lower, conventionally using and detect antibody as the sign infecting clinically.After pathogenic infection body, the appearance of antibody still for some time, detects antibody at this window phase and occurs undetectedly, and antigen can detect.But after lot of antibodies occurs in serum, be combined with antigen and form antigen antibody complex, can seal the free antigen in serum, make free antigen be difficult for detecting.If can improve the recall rate of antigen by detecting corresponding antigens after antigen antibody complex dissociation, thereby reach the object of early diagnosis.
As hepatitis C virus, antigen is the positive evidence that the third liver infects, and can be used as the evaluation index of the third liver result for the treatment of, but when body produces after antibody, due to the existence of immune complex, the recall rate of antigen is reduced greatly, the objective reality evaluation of impact to the third liver result for the treatment of.And for example the pre-s1 protein of hepatitis type B virus (HBV) plays an important role in Virus entry liver cell process, pre S 1 antigen can be used as virus sweep and viral index of turning out cloudy, and it is larger that the hepatitis B patient of the pre S 1 antigen positive is propagated hepatitis type B virus danger more negative than pre S 1 antigen and asymptomatic HbsAg carrier; And anti-former S 1 immune body has the hepatitis B of prevention enter liver cell breeding and remove viral effect, its sun in serum turns the infectants such as indication HBsAg and pre S 1 antigen and all can turn out cloudy smoothly, disease is rehabilitation morning, its early stage preact is unique in all indexs of hepatitis B, so it has very large using value in the laboratory diagnosis of hepatitis B; If but formed pre S 1 antigen antibody mediated immunity compound, can have influence on detecting of the two, to two indexs, all cannot accomplish accurate evaluation.If therefore have kind for the treatment of fluid can make above-mentioned immune complex dissociate and not affect its immunogenicity, and all can accurately be detected, there is important clinical meaning.
At present, there is research for the sample processing method of the free and antibody that destruction is combined with HCV antigen of HCV antigen, as mono-kind of patent < < measures the method > > (CN101017172A of all-core antigen of hepatitis C virus, open day 20070815) disclose a kind of for measuring all-core antigen of hepatitis C virus pretreatment fluid, this pretreatment fluid formula is 0.3%TritonX100, the Tris-HCL of 1.5%SDS and 0.1M, pH8.0.But this processing mode is applicable to the detection of HCV all-core antigen, whether it has destruction to antibody in immune complex, whether is applicable to other detection that detects index immune complex and does not mention.And the processing mode of mentioning in this patent is to sample this 100ul, with pretreatment fluid 100ul, in 56 ℃ of processing 30min.Because reaction time of existing enzyme immunity or electrochemiluminescent immunoassay mostly is 37 ℃, treatment conditions be 56 ℃ need to use separately other warm bath equipment or must be in existing same temperature bath equipment intensification cooling repeatedly process and (while processing sample, obtain first warm bath temperature is raised to 56 ℃, and after handling, for subsequent experimental needs again to cool the temperature to 37 ℃, be not easy to operation).We are at patent < < antigen antibody complex dissociation liquid kit and the application > > (publication number: CN101832999A of application in the past, applying date 2010.04.29) also have the same problem of processing inconvenient operation, its processing mode is also 56 ℃ and processes 30min.
There is dissociation solution that document mentioned employing 0.1mol/L Gly-HCl (pH2.2), 5%CHAPS, 7%Tritonx-100 preparation to the sample 30min that dissociates, can make HAV, the HCV antigen antibody complex dissociate in the time of 37 ℃.But the detection to antigen detection type sample has still only been studied in this research, other virus antigen-antibody immune complexs especially antagonist are detected to whether have effect same, or whether likely destroy antibody all not in checking.And the concentration that in the document, CHAPS used and Tritonx-100 are used is very large, saturated solution under CHAPS normal temperature is 5%, Tritonx-100 is under 6.0 to 8.0 normal temperature time at pH, its aqueous solution is 5%, the acidic buffer of the pH2.2 adopting in the document dissolves, although can reach the effect of dissolving and dissociating.But those skilled in the art can expect this scheme and when washing plate, can produce a large amount of dense thick foams and easily cause and wash plate machine and stop up, in addition the long-term use of the acidity of pH2.2 easily causes that to wash plate machine pipeline aging, so this scheme is not suitable for clinical medium-term and long-term routine testing and uses.
List of references:
1, < < method > > (CN101017172A, open day 20070815) who measures all-core antigen of hepatitis C virus.
2, < < antigen antibody complex dissociation liquid kit and application > > (publication number: CN101832999A, applying date 2010.04.29).
3, the < < immune complex research of the agent analyzing of applying effects > > (Yang Rong in HCV antigen detects that dissociates, Long Run township, Li Hua etc. Journal of Immunology [J] .2012,7 (28): 620-623.).
Summary of the invention
For the deficiencies in the prior art, the problem to be solved in the present invention is to provide antigenantibody complex treatment kits and the application thereof in a kind of serum or plasma sample.
Antigenantibody complex treatment kits in serum of the present invention or plasma sample, by the slant acidity damping fluid as solvent and the salt ion of high concentration, ionic surfactant, non-ionics, reductive agent, urea, trehalose and defoamer are formulated, it is characterized in that: described slant acidity damping fluid is pH6.5 ± 0.2, concentration is the PBS damping fluid of 0.01 ± 0.002M, the salt ion of described high concentration is that concentration is NaCl or the KCl of 0.5 ± 0.02M, described ionic surfactant is 3-[(3-courage amidopropyl) dimethylammonio]-1-propane sulfonic acid salt (CHAPS), 3-[(3-courage amidopropyl) dimethylammonio]-2-hydroxyl-1-propane sulfonic acid salt (CHAPSO), cetyl trimethyl ammonium bromide (CTAB), lauryl sodium sulfate (SDS), dodecyl creatine sodium (sarkosyl) is or/and DTAB (DTAB), described non-ionic surfactant is Tween-20, tritonx-100 or tritonx114, described reductive agent is the reductive agent halfcystine of protein disulfide, dithiothreitol (DTT) (DTT), reduced glutathione or beta-mercaptoethanol (2-Me), described urea is that concentration is the urea of 2.5 ± 0.02M, described trehalose is that concentration is the trehalose of 1.0wt%~2.0wt%, described defoamer is that volumetric concentration is 0.01%~0.015% Antifom204.
In antigenantibody complex treatment kits in above-mentioned serum or plasma sample: the described ionic surfactant 3-[(3-courage amidopropyl that preferably volumetric concentration is 1%) dimethylammonio]-2-hydroxyl-1-propane sulfonic acid salt (CHAPSO) and the volumetric concentration DTAB (DTAB) that is 0.5%.
In antigenantibody complex treatment kits in above-mentioned serum or plasma sample: the described non-ionic surfactant tritonx114 that preferably volumetric concentration is 1%.
In antigenantibody complex treatment kits in above-mentioned serum or plasma sample: the described reductive agent beta-mercaptoethanol (2-Me) that preferably volumetric concentration is 0.5%.
In antigenantibody complex treatment kits in above-mentioned serum or plasma sample: the described trehalose trehalose that preferably concentration is 1.5wt%.
Further, antigenantibody complex treatment kits in serum of the present invention or plasma sample is most preferably by the pH6.5 as solvent, concentration is the PBS damping fluid of 0.01M and the KCl of 0.5M, volumetric concentration is 1% 3-[(3-courage amidopropyl) dimethylammonio]-2-hydroxyl-1-propane sulfonic acid salt (CHAPSO) and the volumetric concentration DTAB (DTAB) that is 0.5%, volumetric concentration is 1% tritonx114, volumetric concentration is 0.5% beta-mercaptoethanol (2-Me), the urea of 2.5M, the trehalose of 1.5wt%, volumetric concentration is that 0.01% Antifom204 is formulated.
The application of the antigenantibody complex treatment kits in serum of the present invention or plasma sample, it is characterized in that: by sample, be that antigenantibody complex mixes in the ratio of 100ul:50ul with the treating fluid in kit of the present invention, the mode of processing sample is: room temperature treatment 30min, 37 ℃ of processing 15min or 56 ℃ of processing 15min.
Wherein: the mode of preferably processing sample is: room temperature treatment 30min or 37 ℃ of processing 15min.
The application of the antigenantibody complex treatment kits in serum of the present invention or plasma sample, it is characterized in that: kit of the present invention is except processing sample as sample preparation liquid separately, can also as the sample diluting liquid in adding ingredient and available reagent box by volume the ratio of 1:10 directly add, together use with sample diluting liquid, can reach certain dissociation effect equally.
Antigenantibody complex treatment kits in serum of the present invention or plasma sample is applicable to doubtful generation antigenantibody complex and affects the serum of detection effect or the processing of plasma sample of antigen or antibody, the sample detection that serum after processing with kit of the present invention or plasma sample are applicable to enzyme linked immunological, chemiluminescence immunoassay etc., the sample that does not produce immune complex does not affect normal detection effect after kit treating fluid of the present invention is processed.
The antigenantibody complex treatment kits of the present invention established antigenantibody complex in sample that can effectively dissociate, greatly improved the detection sensitivity of sample, there is high clinical value, and can be widely used in all types of Samples.
Embodiment
Embodiment 1: the research preparation of immune complex sample treatment solution
In the present embodiment, its processing mode is all with reference to the processing mode in the patent that the applicant was CN101832999A at publication number in the past, being the 100ul sample reagent that adds 50ul preparation processes after 30min in 56 ℃, more then by each coherent detection kit, detects.
(1) damping fluid is selected
The association reaction of antigen and antibody is reversible, what antibody and antigen formed is compounded under certain external environment as under low pH, high salt concentration, multigelation, antigen antibody complex also can be dissociated, in the situation that processing is proper, the antigen-antibody after dissociating still keeps original structure, activity and specificity.Wherein changing pH and ionic strength is the method that the most frequently used promotion is dissociated.
In view of above-mentioned principle, first the present embodiment is adjusted pH value and ionic strength, finds when the pH value of PBS is down to 6.5, and NaCl concentration is risen to after 0.5M, and detection sensitivity has been had to significant raising.
The results are shown in Table 1 and table 2.
Table 1: different PBS and the Contrast on effect of NaCl concentration to HCV antigen detection sensitivity
Table 2: different PBS and NaCl concentration detect the impact of effect on HBV former S 1 immune body
(2) activating agent is selected
In order to study immune complex sample treatment solution, whether can improve the sensitivity of immune complex class sample when the coherent detection, first take above-mentioned 1 * PBS (pH6.5) 0.5M NaCl as basis, again various components to be compared are added wherein as ion-type activating agent, nonionic agent, protein denaturant and other salt etc., with hepatitis C antigen, detect respectively and the S/CO value of former S 1 immune body detection (being the CUTOFF value of the OD value/separately of sample) is assessed, sample type is HCV antibody positive sample, former S 1 immune body positive sample.
Because ionic surfactant can destroy the interaction between albumen, and non-ionic surfactant is as energy solubilizing lipids such as Tritonx-100, strengthen the permeability of antibody to film, antibody is come out, and more easily detect, so by some common ion-types and non-ly join in basic damping fluid from surfactant.
In the sample treatment solution that different activating agents adds as shown in table 3 and table 4, sensitivity is had the change of distinct program degree, and the amount adding is different, its intensity of variation also differs.
After table 3 different activities agent processing sample, HCV antigen is detected the impact of effect
Note: it is 10 through HCV RNA virus load that sample used is 5 parts
3to 10
5between and the positive sample of HCV antibody test mix rear test, all do 3 parallel holes, the mean value that samples this OD value calculates S/CO value.
After table 4 different activities agent combined treatment sample, HCV antigen is detected the impact of effect
Note: sample used is consistent with sample used in table 3.
(3) protective effect of trehalose
The use of a large amount of activating agents and denaturant can make sensitivity improve existing relevant report in hepatitis C antigen context of detection, but it is antibody is destroyed and make antigen free to improve sensitivity that many documents also propose this, but the impact of antagonist not studies have reported that, how when using activating agent and denaturant dissociated antigen antibody, to make antigen-antibody all keep active, also have no report.
Trehalose is with a by two glucose molecules; a; 1,1-glycosidic bond forms nonreducing sugar, and self property is highly stable; trehalose has magical protective effect to biosome; because trehalose can form unique diaphragm at cell surface, protected protein matter molecule unchangeability inactivation effectively, thereby the life process of the body that sustains life and biological characteristic; and other carbohydrates such as sucrose, glucose all do not possess this function.In order to make albumen both reach the effect of dissociating under the state of sex change; after keeping again dissociating, antigen and antibody can keep original activity; we try to add trehalose in treating fluid; but trehalose addition does not have protective effect less; addition is many may hinder dissociation effect, so we have done to study in great detail to the interpolation of trehalose and interpolation concentration.Discovery is along with the interpolation of trehalose can play a protective role, but the reason that may dissociate because of certain obstruction over finite concentration can make detected value decline, and the 1.5%th, optium concentration.
The results are shown in Table 5.
Table 5 trehalose detects the impact of effect on c-hepatitis antibody after dissociating
Note: the positive sample detecting is 10 parts of antibody positive samples, calculating mean value, compares with critical value separately.
(4) interpolation of reductive agent
Applicant studies discovery, reductive agent be added with beyond thought great effect.On the one hand, it is improved sensitivity, and on the other hand, it has certain effect to eliminating false positive.Because coated albumen is gene engineering antigen if, in synthetic peptide in preparation process, if some peptide sequence mistake can cause synthetic peptide specificity to change and produces false positive.Take hepatitis C antigen or antibody test as example, the main epi-position section NS3 antigen of hepatitis C (HCV) contains a plurality of cysteine residues (only aa1196-1473 just has 7 Cys), when recombinant expressed, this albumen may form the disulfide bond of mispairing, thereby change native conformation, cause on the one hand NS3 antigen active to reduce, and cause sensitivity, decline, another side produces false positive because native conformation change changes specificity; Core (CORE) epitope also causes activity decreased because exposure is insufficient.And the interpolation of reductive agent can reduce albumen dislocation disulfide bond and change protein conformation, improve activity and the specificity of antigen, sensitivity and specificity are all had greatly improved, change because of disulfide bond simultaneously makes to be opened by the folded state of Reichl's test, become flattened state, detection site is better exposed because being opened, can greatly improve detection sensitivity.Therefore the interpolation of reductive agent, makes antigenantibody complex treating fluid of the present invention obtain beyond thought great effect.
In the present invention, the reductive agent of indication refers to the reductive agent of Reduction of Disulfide, and it is including but not limited to halfcystine, dithiothreitol (DTT) (DTT), reduced glutathione, beta-mercaptoethanol (2-Me) etc.DTT and 2-Me are the sulfhydryl reagent of the most frequently used reductive agent as disulfide bond, in stability assessment experiment, applicant finds, DTT is relatively more poor than 2-Me stability as mentioned in many reports, the ability of its Reduction of Disulfide is suitable with 2-Me in this kit, and unlike some report, mention be better than 2-Me far away.
The results are shown in Table 6.
Table 6DTT and 2-Me detect the impact of effect on c-hepatitis antibody
(5) interpolation of protein denaturant urea (Urea)
Peptide chain in native protein molecule coils complications in some way, forms specific conformation.Maintaining of this conformation, mainly depends on the hydrogen bond in protein molecule.Urea can destroy hydrogen bond, causes protein molecular structure lax, makes protein denaturation, and after sex change, the peptide chain of protein just extends, thereby make originally to contain at intramolecular-SH, expose, can with sulfhydryl reagent effect.So after having added reductive agent 2-Me, then add urea, can play better synergy.The results are shown in Table 7.
Normal serum detection of anti-HCV ELISA is owing to being subject to the various factors such as RF in serum can occur false positive results once in a while.
Table 7Urea detects the impact of effect on the third liver
Note: the positive sample detecting is 10 parts of antigen positive samples, 10 parts of antibody positive samples, each calculating mean value, then compare with critical value separately.
(6) Main Components of antigenantibody complex treatment kits and ultimate density are determined
Based on above-mentioned achievement in research, Main Components and the ultimate density of after applicant sums up, having determined immune complex sample treatment solution are as follows: damping fluid is PBS damping fluid damping fluid (PH6.5), working concentration is 0.01M, 1%CHAPSO, 0.5%CTAB, 1%Tritonx-114,0.5%2-Me, 2.5M Urea.
In addition we study and find 0.5M NaCl to replace to 0.5M KCl, can not change detection effect, but the solubleness of each component is improved greatly, the another 0.01%Antifom204 of interpolation can eliminate a large amount of foams that the interpolation due to various activating agents produces when detecting effect greatly not affecting, and reduces the stifled pin risk while washing plate.
Determining of embodiment 2 antigenantibody complex treatment kits optimum treatment modes
(1) preparation of antigenantibody complex
Reference literature, preparation HAV(hepatitis A virus) immune complex, to verify dissociation effect and dissociate Best Times and the temperature of the antigenantibody complex treatment kits of embodiment 1 preparation.
To add the HAV antiserum of necessarily tiring in certain density HAV antigen, before adding and after neutralization, with HAV antigen detection kit (self-control kit), detect respectively, in the HAV antigen that is 160EU/ml in concentration, add the antiserum of tiring as 20U/ml, before adding antiserum, with HAV antigenic reagent box, detecting OD value is 0.821, and adding OD value after the antiserum of 20U/ml is 0.087.
(2) optimum treatment mode determines
Application antigenantibody complex treatment kits is dissociated to HAV antigen antibody complex under different temperatures and time, and test mode is as follows:
Divide the immune complex 100ul that gets preparation, respectively add 50ul antigenantibody complex reagent treatment, respectively at room temperature 15min, 30min, 45min, 60min; 37 ℃ of 15min, 30min, 45min, 60min; 56 ℃ of 15min, 30min, 45min, 60min detects with HAV antigen detection kit after processing again.The results are shown in Table 8.
The comparative study in table 8 treatment temperature and processing time
The above-mentioned contrast of process is found: room temperature treatment 30min, 37 ℃ of processing 15min and 56 ℃ of processing 15min all can reach good treatment effect, and approach the plateau room temperature treatment 30min dissociating, 37 ℃ of processing 15min, can better adapt to actual demand.
Embodiment 3 treating agent of the present invention also can be obtained dissociation effect as the interpolation composition of sample diluting liquid
By comparative study in embodiment 2, find that it dissociates is that temperature of reaction raises or the reaction time extends degree of dissociation is increased, until reach or approach plateau.Based on this, whether degree of dissociation is along with the addition of antigenantibody complex reagent treatment and time and change, and the present embodiment has further been done checking, and temperature of reaction is defined as 37 ℃, the results are shown in Table 9.
The comparative study in table 9 treating agent adding proportion and processing time
The above results shows, 37 ℃ of 100ul sample+50ul treating agents are processed 15min and are still optimum treatment mode (because its reaction time is short, easy to operate); But 100ul sample+10ul treating agent processing 60min also can reach well and dissociate under 37 ℃ of conditions, therefore we guess, if by treating agent with certain proportion as with sample diluting liquid in 1:10(volume ratio) ratio directly add in the middle of sample diluting liquid and together use with sample diluting liquid, whether also can reach certain dissociation effect.We all verify in detections such as the detection of HAV antigen, the detection of HCV antigen, HCV antibody test, HBV former S 1 immune bodies respectively this scheme, find all to have obtained certain dissociation effect.The results are shown in Table 10~13.
Table 10 treating agent 1:10 adds the research in HAV antigen detection kit sample diluting liquid
Internal control product |
The rare treating agent that do not add of sample |
The rare interpolation treating agent of sample |
P1 |
0.252 |
0.596 |
P2 |
0.456 |
0.511 |
P3 |
0.221 |
0.372 |
P4 |
0.337 |
0.486 |
P5 |
0.453 |
0.535 |
Table 11 treating agent 1:10 adds the research in HCV antigen detection kit sample diluting liquid
Internal control product |
The rare treating agent that do not add of sample |
The rare interpolation treating agent of sample |
P1 |
0.183 |
0.277 |
P2 |
0.211 |
0.324 |
P3 |
0.302 |
0.391 |
P4 |
0.456 |
0.613 |
P5 |
0.213 |
0.378 |
Table 12 treating agent 1:10 adds the research in HCV antibody assay kit sample diluting liquid
Internal control product |
The rare treating agent that do not add of sample |
The rare interpolation treating agent of sample |
P1 |
0.371 |
0.421 |
P2 |
0.432 |
0.534 |
P3 |
0.267 |
0.365 |
P4 |
0.269 |
0.370 |
P5 |
0.567 |
0.628 |
Table 13 treating agent 1:10 adds the research in HBV former S 1 immune body detection kit sample diluting liquid
Internal control product |
The rare treating agent that do not add of sample |
The rare interpolation treating agent of sample |
P1 |
0.237 |
0.356 |
P2 |
0.182 |
0.327 |
P3 |
0.388 |
0.435 |
P4 |
0.182 |
0.342 |
P5 |
0.291 |
0.425 |