1. Regarding immunity, the wrong thing is: ()
A. Resist the invasion of pathogens
B. Can prevent the occurrence of tumors
C. Remove its own aging dead cells
D. Always beneficial to the body
E. Maintain internal environment stability
2. Specificity of antigen-antibody reaction It refers to the specificity of binding between the antigenic determinant and which region of the antibody molecule: ()
A. Variable region
B. Constant region
C. High Variable region
D. Hypervariable region
E. Hypovariable region
3. Which of the following methods is best used to identify the titer of an antibody: ()
A. Indirect agglutination test
B. One-way immunodiffusion method
C. Two-way immunodiffusion method
D. Immunoaffinity chromatography
E. Polyacrylamide gel electrophoresis
4. The criterion for judging the potency of test tube agglutination test is based on the following agglutination phenomenon visible to the naked eye: ( )
A.? ?
B.? Or?
C.? ?
D.? ?
E.? ?
5. Regarding the direct method of preparing radiolabeled conjugates, which of the following statements is correct: ()
A. 125I and protein through small molecule carriers Binding
B. Can label all proteins or polypeptides
C.125I labeling has no effect on protein activity
D. The commonly used oxidizing agent is chloramine T
The specific radioactivity of E.125I marker is low
6. What directly affects the test results in fluorescence microscopy is: ()
A. Antigen fluorescence Staining
B. Antibody fluorescent staining
C. Complement fluorescent staining
D. Specific fluorescent staining
E. Non-specific fluorescence Dyeing
Reference answers and analysis
1. Refer to answer D. Analysis: Immunity is not always beneficial to the body. When the immune defense function is too strong, a hypersensitivity reaction will occur, which is harmful to the body. It is beneficial under physiological conditions and harmful under pathological conditions.
2. Refer to answer D. Analysis: Antibody molecules are divided into constant regions and variable regions based on heavy and light chains. The variable region composed of light chains can be divided into hypervariable regions and framework regions. Hypervariable regions can specifically bind to antigenic determinants. Control the specificity of the antibody.
3. Refer to answer C. Analysis: The two-way immunodiffusion method is commonly used to identify the antibody titer. One is to only dilute the antiserum and react with the antigen of a uniform concentration; the other is to dilute the antiserum and the antigen at the same time. After free diffusion, a precipitation line is formed to appear. The antibody dilution with the highest precipitation line has the titer of the antibody.
4. Refer to answer C. Analysis: The criterion for judging the potency of the test tube agglutination test is based on the obvious agglutination phenomenon visible to the naked eye ( ).
5. Refer to answer D. Analysis: The oxidizing agent commonly used in the direct preparation of radiolabeled conjugates is chloramine T. Chloramine T is a mild oxidant that produces hypochlorous acid in aqueous solution to oxidize I. The method is simple, rapid, efficient and reproducible.
6. Refer to answer E. Analysis: Non-specific fluorescent staining is an interference factor in fluorescent staining that will directly affect the test results.