complement fixation assay

The determination of complement includes determination of total complement, hemolytic activity, individual complement components and complement fragment size, and complement participation in the assay. The antigen-antibody complex is combined with complement, and the phenomenon that the concentration in the complement reaction solution containing the known concentration is consumed to reduce the concentration to detect the antigen or the antibody is one of the methods for detecting the high sensitivity, especially according to the method. This method can also be used when the antigen-antibody reaction cannot be observed by a precipitation reaction or an agglutination reaction. Basic Information Specialist classification: Infectious disease inspection and classification: pathogenic microorganism inspection Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: Normal value, negative, ie 0 to 1:10. Prompt not infected with an infectious virus. Positive: A positive indication is infected by an infectious virus. Tips: The operation steps are complicated and the requirements are very strict. If you are slightly negligent, you will get incorrect results. Normal value Normal value: 0 to 1:10. Clinical significance Abnormal results: >1:10 was positive, and the coincidence rate for diagnosis of brucellosis was 97.96%. Complement binding assays can be applied in the following ways: 1 infectious disease diagnosis. Detection of pathogenic antigens and corresponding antibodies. 2 detection of other antigens. For example, tumor-associated antigens, protein identification in blood, HLA typing, and the like. 3 autoantibody detection. Precautions The operation should be careful and accurate; the glass equipment must be very clean; the known ingredients involved in the test must be titrated in advance and used to the specified concentration to ensure reliable results. Inspection process (1) Titration of blood: 1 Take 1ml of complement, add 9ml of BBS, and then dilute to 1:20, 1:30, 1:40, 1:50, 1:60, 1:80, 1:100, 1:200, 1:400, and take 50 0.2 ml of hemolysin, add 9.8 ml of BBS, which is 1:100 hemolysin, and then continue to dilute to 1:800, 1:1600, 1:3200, 1:6400. 2 Take the square array of test tubes, longitudinally add 0.1ml of different concentrations of complement, and add 0.1ml of hemolysin in each row (all should be added from the highest dilution), then add BBS0.2ml, complement and The hemolysin control tubes were each added with BBS 0.3 ml, and finally 2% sheep red blood cells were added to each tube. The total amount of each tube was 0.5 ml, shaken, placed in a 37 ° C water tank for 30 min, and the results were observed. The highest dilution of complete hemolyzed complement and hemolysin is the respective unit. In practical applications, hemolysin is used in 2U (3200÷2=1600) and complement is used in 2.5U (80÷2.5=32). (2) Formal test: 1 Operate with a V-type microplate, and make a test well for each specimen. A serum control well. BBS0.025ml was added to each well. 2 Dip serum (0.025 ml) with a dilution stick to the first well, rotate and transfer to the second well for a total of eight wells, thus obtaining a 1:2 to 1:256 dilution. An example of a complement binding assay for measuring antibodies by a small amount is described. Gradually add various reagents, observe the various control tubes after incubation, and should be consistent with the expected results. Negative and positive control tubes should be clearly hemolyzed and non-hemolyzed; antibody or antigen control tubes, serum control tubes to be tested, and control tubes of positive and negative controls should be completely hemolyzed. Spontaneous hemolysis should not occur in sheep red blood cell control tubes. The complement control tube should show 2U for total dissolution, 1U for total dissolution with a little red blood cells, and 0.5U should be insoluble. For example, the complete dissolution of the 0.5U complement control indicates that the amount of complement is excessive; if the 2U control tube does not show hemolysis, indicating that the amount of complement is insufficient, the results are affected, and the test should be repeated. The results of the complement fixation test showed that the test serum was not hemolyzed and the hemolysis was negative. Not suitable for the crowd Those who do not have an indication for examination should not do this check. Adverse reactions and risks Generally no complications and harm.