Agglutination assay

The agglutination test is one of the serological test methods. The serological test is a general term for the visible reaction of antigen and antibody in vitro, so it is also called antigen-antibody reaction. It can detect unknown antigens (bacteria to be tested) with known antibodies (bacterial antiserum); it can also detect the corresponding antibodies and their titers in the serum of patients with known antigens (known pathogens), which is clinical diagnosis, laboratory research and One of the important means of bacteriological identification. Basic Information Specialist classification: Infectious disease examination and classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: The bacteria to be tested and the control bacteria were uniformly turbid. Positive: The bacteria to be tested were obviously agglutinated, and the control bacteria were uniformly turbid. Tips: Pay attention to normal eating habits and pay attention to personal hygiene. Normal value The type and proportion of the flora in the body are normal, and the human body is in a state of dynamic balance and health. Clinical significance For identification of strains and bacterial types, Staphylococcus, Streptococcus pneumoniae, Salmonella, Shigella, pathogenic Escherichia coli, Vibrio cholerae, Neisseria meningitidis and so on. Abnormal results: Streptococcus pneumonia caused diseases such as lobar pneumonia; meningitis caused by Neisseria meningitidis; various intestinal diseases caused by pathogenic Escherichia coli; caused by staphylococci; caused by Salmonella; Caused by Shigella; caused by Vibrio cholerae. People who need to be examined: Staphylococcus, Streptococcus pneumoniae, Salmonella, Shigella, Pathogenic Escherichia coli, Vibrio cholerae, Neisseria meningitidis and other bacterial infections. Positive results may be diseases: pediatric pseudomembranous colitis, neutral white (granulocytopenia), brucellosis, acquired bullous epidermolysis, Campylobacter infection, pseudomembranous colitis, elderly aspiration pneumonia matter Forbidden before examination: Pay attention to normal eating habits and pay attention to personal hygiene. Requirements for inspection: Actively cooperate with the doctor. Inspection process 1. Slide method: commonly used to identify strains and bacterial types, such as staphylococcus, Streptococcus pneumoniae, Salmonella, Shigella, pathogenic Escherichia coli, Vibrio cholerae, Neisseria meningitidis, etc. Identification. (1) Principle: The known diagnostic serum or plasma is mixed on the slide with the test bacteria and physiological saline. If a specific agglutination block visible to the naked eye appears, the bacteria is the corresponding bacteria. (2) Method: Take a clean glass slide, take the culture to be tested with the inoculation loop, mix with the diagnostic serum and physiological saline, shake the slides up and down several times, and observe the results after l~3min. (3) Judgment of results: Positive one is obviously agglutinated, and the control bacteria are evenly turbid. Negative one to be tested and the control bacteria were evenly turbid. Self-coagulation one test bacteria and control bacteria all agglutinated. (4) Note: Some bacterial bacteria often have a surface antigen on the surface, such as the vi antigen of Salmonella typhimurium and the K antigen of Shigella. It inhibits the agglutination of bacterial antigens and antisera, leading to false negative results. At this point, the bacterial suspension should be boiled at 100 ° C for 1 h to destroy its surface antigen and then tested. 2. Test tube method: This method can exclude the non-specific agglutination of the slide method agglutination test, which is a semi-quantitative agglutination test. (1) Method: Take 10 small test tubes, add 0.45ml of normal saline to the first tube, add 0.05ml of diagnostic serum, mix the other tubes with normal saline 0.25m|, then aspirate 0.25ml from the first tube. In the second tube, after mixing, 0.25 ml was added to the third tube, and then to the ninth tube, and 0.25 ml was withdrawn from the ninth tube, and the anti-serum was not added as the control tube. Add 0.25 ml of the bacteria solution to be tested in each tube, mix thoroughly and shake, and place in a 37 ° C water tank bath for 4 h, then set at 4 ° C overnight. (2) Judgment of results: The highest dilution of serum reached (++) agglutination (the liquid in the tube was clarified, and some agglomerates sinked to the bottom of the tube) as the agglutination titer of the bacteria. If the titer used for the original diagnostic serum titer is more than half of the positive. (3) Note: The bacterial solution of Neisseria meningitidis must be inactivated at 56 ° C for 30 min to destroy the autolytic enzyme. If the test has a low agglutination result, the bacteria should be subcultured several times before testing. Not suitable for the crowd Inappropriate crowd: temporarily unknown. Adverse reactions and risks There are no related complications and hazards.

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