Complement valence liposome immunoassay kit and preparation and use method thereof
1. A complement valence liposome immunoassay kit is characterized by comprising two liquid components of a reagent R1 and a reagent R2 which are independent from each other, and the kit comprises the following components in parts by weight:
reagent R1:
20 to 40 percent of immunoliposome
10-100 mmol/L buffer solution
0.1-1 g/L of preservative
The solvent is purified water;
reagent R2:
the solvent is purified water.
2. The complement valence liposome immunoassay kit of claim 1, comprising the following components and corresponding contents:
reagent R1:
immunoliposome 33%
Buffer 50mmol/L
0.5g/L preservative
The solvent is purified water;
reagent R2:
the solvent is purified water.
3. The kit for immunoassay of complement valence liposomes according to any one of claims 1 to 2, wherein the immunoliposome in the reagent R1 is CH50 immunoliposome.
4. The complement valence liposome immunoassay kit of claim 3, wherein said CH50 immunoliposome is prepared by the following method: mixing water-soluble glucose 6 phosphate dehydrogenase, soybean phospholipid, cholesterol and the derivatized DNP antigen in purified water to prepare a water phase, and then filtering the water phase through a microporous filter membrane; after filtering, the filtrate is freeze-dried and dehydrated, and then rehydrated to obtain the CH50 immunoliposome required by the reagent.
5. The complement valence liposome immunoassay kit according to any one of claims 1 to 2, wherein the buffer is one or more of Tris-HCL buffer, PBS buffer, PB buffer and HEPES buffer.
6. The complement valence liposome immunoassay kit according to any one of claims 1 to 2, wherein the preservative is one or more of thimerosal sodium, sodium azide and gentamicin sulfate.
7. A method for preparing the complement valence liposome immunoassay kit according to any one of claims 1 to 6, comprising the steps of:
(1) preparation of immunoliposomes
Mixing water-soluble glucose 6 phosphate dehydrogenase, soybean phospholipid, cholesterol and the derivatized DNP antigen in purified water to prepare a water phase, and then filtering the water phase through a microporous filter membrane; after filtering, freeze-drying and dehydrating the filtrate, and rehydrating to obtain the immunoliposome required by the reagent;
(2) preparation reagent R1
Mixing the immunoliposome prepared in the step (1) and the rest other component substances in the same container according to the component content of the reagent R1, and uniformly mixing to prepare a reagent R1;
(3) preparation reagent R2
According to the component content of the reagent R2, all the components are mixed in the same container, and after uniform mixing, the reagent R2 is prepared.
8. A method of using the complement valence liposome immunoassay kit according to any one of claims 1 to 6, comprising the following specific steps:
(1) sucking 10 μ L of sample, adding 250 μ L of reagent R1, and incubating at 37 deg.C for 5 min;
(2) adding 125 μ L of reagent R2, mixing, and allowing them to react thoroughly;
(3) reading a light absorption value Al after 1min, reading a light absorption value A2 after 3min, and calculating delta A;
(4) and calculating the complement valence content in the sample according to the absorbance change value delta A.
9. A method of using the complement valence liposome immunoassay kit according to claim 8, wherein in the step (3), the absorbance is measured at a main wavelength of 340nm and a sub-wavelength of 700nm using a full-automatic biochemical analyzer.
10. A method of using the complement valence liposome immunoassay kit according to claim 8, wherein in the step (4), the complement valence content in the sample is measured based on Δ A based on the calibration value; the calibration method comprises the following steps: and 5, calibrating at a point, detecting by adopting a full-automatic biochemical analyzer, and setting the concentrations of the calibrators to be respectively: 0U/mL, 37.5U/mL, 75U/mL, 150U/mL, 300U/mL.
Background
The total complement activity assay is used for typical immune complex-mediated diseases such as Systemic Lupus Erythematosus (SLE), glomerulonephritis, autoimmune hemolytic anemia, and the like, in addition to clinical diagnosis of genetic complement deficiency. Since chronic activation of immune complexes results in a secondary decrease in serum total complement activity (CH50) and levels of complement components, detection of complement activity provides an important basis for the progression and efficacy of such diseases. Currently, hemolysis is mainly used for the determination of total complement activity. The hemolysis method is the gold standard in the field and has good application advantages, but the method has the defects of troublesome operation, long time consumption, difficult quantification and the like.
Liposome Immunoassay (LIA) is a novel immunological detection method originated by Ka-atoka scholars in the early seventies of the twentieth century. In recent years, with the deep discussion of membrane dissolving mechanism and the correct application of the biological membrane structure theory in liposomes, LIA has been developed to a new stage, and has attracted people's attention. The liposome immunoassay method has the advantages of simple operation, rapid detection, high sensitivity, good specificity, quantitative detection and the like.
When an antigen or antibody molecule is bound to the surface of a liposome, it is called an Immunoliposome (Immunoliposome). The liposomes of LIA are typically immuno-encapsulated liposomes with complex phospholipid components, mostly large unilamellar Liposomes (LUV) and small unilamellar liposomes (SUV). With the progress of liposome preparation methods and protein crosslinking technologies, people can prepare liposomes of different sizes, layers, chargeability and phospholipid according to needs, so that a certain amount of markers are wrapped in the liposomes, and immune molecules with specific groups are crosslinked on the surfaces of the liposomes.
Therefore, if the liposome immunoassay method can be used for detecting the complement activity, the defects of the traditional hemolysis method can be overcome, and a new method for detecting the complement activity is obtained.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a complement valence liposome immunoassay kit and a preparation and use method thereof, which can avoid the problems of troublesome operation, long time consumption and difficult quantification caused by the adoption of a traditional hemolysis method.
The invention adopts the following technical scheme to solve the technical problems:
a complement valence liposome immunoassay kit comprises a reagent R1 and a reagent R2 double liquid components which are independent from each other, and comprises the following components in corresponding content:
reagent R1:
20 to 40 percent of immunoliposome
10-100 mmol/L buffer solution
0.1-1 g/L of preservative
The solvent is purified water;
reagent R2:
the solvent is purified water.
As one of the preferable modes of the invention, the components and the corresponding contents are specifically as follows:
reagent R1:
immunoliposome 33%
Buffer 50mmol/L
0.5g/L preservative
The solvent is purified water;
reagent R2:
the solvent is purified water.
In a preferred embodiment of the present invention, the immunoliposome of the reagent R1 is a CH50 immunoliposome.
In a preferred embodiment of the present invention, the CH50 immunoliposome is prepared by the following steps: mixing water-soluble glucose 6 phosphate dehydrogenase, soybean phospholipid, cholesterol and the derivatized DNP antigen in purified water to prepare a water phase, and then filtering the water phase through a microporous filter membrane; after filtering, the filtrate is freeze-dried and dehydrated, and then rehydrated to obtain the CH50 immunoliposome required by the reagent.
As one of the preferable modes of the invention, the buffer solution is one or more of Tris-HCL buffer solution, PBS buffer solution, PB buffer solution and HEPES buffer solution.
In a preferred embodiment of the present invention, the preservative is one or more of thimerosal sodium, sodium azide and gentamicin sulfate.
The preparation method of the complement valence liposome immunoassay kit comprises the following steps:
(1) preparation of immunoliposomes
Mixing water-soluble glucose 6 phosphate dehydrogenase, soybean phospholipid, cholesterol and the derivatized DNP antigen in purified water to prepare a water phase, and then filtering the water phase through a microporous filter membrane; after filtering, freeze-drying and dehydrating the filtrate, and rehydrating to obtain the immunoliposome required by the reagent;
(2) preparation reagent R1
Mixing the immunoliposome prepared in the step (1) and the rest other component substances in the same container according to the component content of the reagent R1, and uniformly mixing to prepare a reagent R1;
(3) preparation reagent R2
According to the component content of the reagent R2, all the components are mixed in the same container, and after uniform mixing, the reagent R2 is prepared.
Specifically, the "derivatized DNP antigen" in the immunoliposome preparation step, and the "goat anti-DNP antibody" in the reagent R2 can be obtained commercially.
The use method of the complement valence liposome immunoassay kit comprises the following specific steps:
(1) sucking 10 μ L of sample, adding 250 μ L of reagent R1, and incubating at 37 deg.C for 5 min;
(2) adding 125 μ L of reagent R2, mixing, and allowing them to react thoroughly;
(3) reading a light absorption value Al after lmin, reading a light absorption value A2 after 3min, and calculating delta A;
(4) and calculating the complement valence content in the sample according to the absorbance change value delta A.
In a preferred embodiment of the present invention, in the step (3), an absorbance is measured at a main wavelength of 340nm and a sub-wavelength of 700nm using a full-automatic biochemical analyzer.
In a preferred embodiment of the present invention, in the step (4), the complement titer content in the sample is calculated according to Δ a based on the calibration value; the calibration method comprises the following steps: and 5, calibrating at a point, detecting by adopting a full-automatic biochemical analyzer, and setting the concentrations of the calibrators to be respectively: 0U/mL, 37.5U/mL, 75U/mL, 150U/mL, 300U/mL.
The reaction principle of the kit of the invention and complement in a serum sample to be detected is as follows:
the "DNP antigen" assembled on the liposome membrane of CH50 immunoliposome (in reagent R1) first reacted with "goat anti-DNP antibody" (in reagent R2) to form a "DNP antigen-antibody complex"; the "antigen-antibody complex" then further activates "complement" in the serum sample; when complement is activated, it attacks and destroys the liposome membrane, and glucose 6 phosphate dehydrogenase (marker, G-6-PDH) in CH50 immunoliposome is released; the released glucose 6 phosphate dehydrogenase will take part in the reactionThereby causing signal amplification and color reaction.
Compared with the prior art, the invention has the advantages that:
(1) compared with the traditional hemolysis method, the kit provided by the invention uses the immunoliposome to detect the complement content in serum, so that the quantitative detection accuracy is improved; meanwhile, the method can be used for a full-automatic biochemical analyzer, and instruments such as agar plates or test tubes are not needed, so that the operation is simpler, and the detection speed is higher; in addition, the kit is simple and convenient in reagent preparation, and is suitable for large-scale production;
(2) the invention can be used on a full-automatic biochemical analyzer, has low cost and high automation, and saves the detection time; under the conditions of high stability and high precision, compared with similar products, the kit also has higher sensitivity and specificity, and the application value of complement detection is improved.
Drawings
FIG. 1 is a schematic representation of the structure of CH50 immunoliposome of example 4;
FIG. 2 is a graph showing the linear relationship between the kit of the present invention and the commercial complement titer detection kit of example 6;
FIG. 3 is a linear range linear regression plot of the kit of the invention in example 6.
Detailed Description
The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.
Example 1
The complement valence liposome immunoassay kit comprises two liquid components of a reagent R1 and a reagent R2 which are independent from each other, and comprises the following components in corresponding content:
reagent R1:
CH50 immunoliposome 40%
Tris buffer 10mmol/L
Sodium azide 0.1g/L
The solvent is purified water.
Reagent R2:
the solvent is purified water.
The preparation method of the CH50 immunoliposome comprises the following steps: mixing water-soluble glucose-6-phosphate dehydrogenase (G-6-PDH), soybean phospholipid, cholesterol and the derivatized DNP antigen in purified water to prepare a water phase, and filtering the water phase through a microporous filter membrane; after filtering, the filtrate is freeze-dried and dehydrated, and then rehydrated to obtain the CH50 immunoliposome required by the reagent.
Example 2
The complement valence liposome immunoassay kit comprises two liquid components of a reagent R1 and a reagent R2 which are independent from each other, and comprises the following components in corresponding content:
reagent R1:
CH50 immunoliposome 20%
PBS buffer 100mmol/L
Thimerosal sodium 1g/L
The solvent is purified water.
Reagent R2:
the solvent is purified water.
The preparation method of the CH50 immunoliposome comprises the following steps: mixing water-soluble glucose-6-phosphate dehydrogenase (G-6-PDH), soybean phospholipid, cholesterol and the derivatized DNP antigen in purified water to prepare a water phase, and filtering the water phase through a microporous filter membrane; after filtering, the filtrate is freeze-dried and dehydrated, and then rehydrated to obtain the CH50 immunoliposome required by the reagent.
Example 3
The complement valence liposome immunoassay kit comprises two liquid components of a reagent R1 and a reagent R2 which are independent from each other, and comprises the following components in corresponding content:
reagent R1:
CH50 immunoliposome 33%
HEPES buffer 50mmol/L
Gentamicin sulfate 0.5g/L
The solvent is purified water.
Reagent R2:
the solvent is purified water.
The preparation method of the CH50 immunoliposome comprises the following steps: mixing water-soluble glucose-6-phosphate dehydrogenase (G-6-PDH), soybean phospholipid, cholesterol and the derivatized DNP antigen in purified water to prepare a water phase, and filtering the water phase through a microporous filter membrane; after filtering, the filtrate is freeze-dried and dehydrated, and then rehydrated to obtain the CH50 immunoliposome required by the reagent.
Example 4
The preparation method of the complement valence liposome immunoassay kit of the embodiment 1 to 3 comprises the following steps:
(1) preparation of CH50 immunoliposomes
Mixing water-soluble glucose 6 phosphate dehydrogenase (G-6-PDH), soybean phospholipid, cholesterol and derivatized DNP antigen in purified water to prepare an aqueous phase, and filtering through a 0.22 μm polycarbonate microporous membrane; after filtering, subpackaging the filtrate in penicillin bottles, placing the penicillin bottles in a cold trap of a freeze dryer, starting the refrigerator, reducing the temperature of the cold trap to about-70 ℃, pre-freezing the sample for 6 hours, starting a vacuum pump, keeping the vacuum degree at about 100mbar, freeze-drying the sample for 24 hours, placing the sample in a tray at the upper part of the cold trap, drying the sample for 2 times at the temperature of about 25 ℃ for 2 hours to obtain a precursor immunoliposome; finally, rehydrating to obtain the CH50 immunoliposome required by the reagent. The structure of the CH50 immunoliposome is shown in figure 1, the liposome membrane of the CH50 immunoliposome is equipped with Deoxyribonuclein (DNP) antigen, and at the same time, glucose 6 phosphate dehydrogenase (G-6-PDH) is included as a marker.
(2) Preparation reagent R1
Mixing the immunoliposome prepared in the step (1) and the rest other component substances in the same container according to the component content of the reagent R1, and uniformly mixing to obtain the reagent R1.
(3) Preparation reagent R2
According to the component content of the reagent R2, all the components are mixed in the same container, and after uniform mixing, the reagent R2 is prepared.
Example 5
This example is a method of using the kit for the immunodetection of complement valence liposomes of the above examples.
The analysis method comprises the following steps: a two-point end-point method;
the reaction direction is as follows: raising reaction;
the calibration method comprises the following steps: Logit-Log (4P);
measuring wavelength: the main wavelength is 340nm, and the auxiliary wavelength is 700 nm;
measuring temperature: 37 ℃;
sample preparation: reagent R1: reagent R2 ═ 10:250:125(μ L);
CH50 calibrator: to BSA was added complement C1100U/mL, complement C250U/mL, complement C350U/mL, complement C450U/mL, complement C550U/mL, complement C650U/mL, complement C750U/mL, complement C850U/mL and complement C950U/mL, and further added thimerosal in an amount of 0.05%, polyvinylpyrrolidone K30 in an amount of 1.5% and sucrose in an amount of 3% by mass.
The testing steps are as follows:
(1) sucking 10 μ L of sample, adding 250 μ L of reagent R1, and incubating at 37 deg.C for 5 min;
(2) adding 125 μ L of reagent R2, mixing, and allowing them to react thoroughly;
(3) reading a light absorption value Al after 1min, reading a light absorption value A2 after 3min, and calculating delta A;
(4) and calculating the complement valence content in the sample according to the absorbance change value delta A.
The method comprises the following steps of measuring and calculating the complement valence content in a sample according to a calibration value and a delta A, wherein the calibration method is 5-point calibration, a full-automatic biochemical analyzer is adopted for detection, and the concentrations of calibrators are respectively set as follows: 0U/mL, 37.5U/mL, 75U/mL, 150U/mL, 300U/mL.
The reaction principle of the kit of the invention and complement in a serum sample to be detected is as follows:
the "DNP antigen" assembled on the liposome membrane of CH50 immunoliposome (reagent R1) is first reacted with "goat anti-DNP antibody" (reagent R2) to formTo "DNP antigen-antibody complexes"; the "antigen-antibody complex" then further activates "complement" in the serum sample; when complement is activated, it attacks and destroys the liposome membrane, and glucose 6 phosphate dehydrogenase (marker, G-6-PDH) in CH50 immunoliposome is released; the released glucose 6 phosphate dehydrogenase will take part in the reactionThereby causing signal amplification and color reaction.
Example 6
The kit for immunoassay of complement valence liposomes of this example has an advantageous effect.
1. And (3) verifying linear correlation:
the reagent prepared by the formula of the embodiment 3 is compared with a detection kit for detecting the complement price of a certain marketed company approved by the State food and drug administration, 100 clinical serum samples are detected, the detection result is shown in the following table 1, and a correlation curve of the detection kit and the detection kit for detecting the complement price of the marketed company is obtained (see fig. 2); the detection result shows that the linear correlation curve of the two kits is y ═ 1.0000x +0.3315, and the correlation coefficient r is 0.99995, which indicates that the two kits have large correlation.
TABLE 1 alignment of the Linear correlation of the kit of the invention (test sample) with the commercially available complement price test kit (as control) from a commercial company
2. And (3) linear range verification:
preparing CH50 calibrators with different concentrations of 5-300U/mL, determining the concentration of each test substance by using the kit, calculating a linear regression equation by using the diluted concentration as an independent variable and the determination result as a dependent variable, and calculating the relative deviation of the determination result. The measurement and calculation results are shown in table 2, and it can be seen from table 2 that the linear regression equation between the measurement results and the dilution concentration is that y is 0.0329+1.0047X (as shown in fig. 3), and the correlation coefficient r is 1.0000, which shows that the linear relationship is good, and the linear range can reach 300 IU/L.
TABLE 2 validation of the Linear Range of the kit of the invention
3. And (3) accuracy verification:
and taking one portion of traceable high-value serum quality control and one portion of traceable low-value serum quality control, detecting for 6 times by using the kit, taking an average value, and comparing with a quality control target value. The results are shown in Table 3, which indicates that the detection values have less relative deviation and higher accuracy than the target values.
TABLE 3 statistical table of accuracy verification results of the kit of the present invention
4. And (3) precision verification:
taking high value and low value of clinical serum samples detected by the kit on sale, continuously detecting the same serum sample for 10 times by using the kit, and calculating the coefficient of variation of the kit. The precision detection data are shown in table 4, and the detection results show that the kit has small variation coefficients of 0.34% and 1.73% respectively and good precision when detecting high-value and low-value samples.
TABLE 4 results of the precision verification of the kit of the present invention
5. And (3) verifying sensitivity and specificity:
a hemolysis method is adopted to detect and screen 50 parts of positive serum and 50 parts of negative serum, a commercially available kit for detecting CH50 by an ELISA method is selected to synchronously detect the 100 parts of serum samples with the kit, then according to the judgment standard of each kit, the samples which are not in the reference standard are set as positive, the samples in the reference standard are set as negative, the hemolysis method is used for detecting the samples as gold standard, and the sensitivity and specificity of each kit are calculated, and the results are shown in Table 5. The result shows that compared with the kit for measuring CH50 by ELISA method, the kit of the invention ensures higher specificity while ensuring sensitivity. The kit has the outstanding advantages of high sensitivity, and compared with the kit prepared by ELISA, the kit has higher specificity, greatly improves the accuracy of clinical detection, and meets the requirement of clinical detection.
TABLE 5 comparison of sensitivity and specificity of the kit of the present invention with those of commercially available kits
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.