1. The following are homogeneous enzyme immunoassays:
A. enzyme amplification immunoassay technique
B. enzyme immunohistochemistry
C. equilibrium assay
D. un-equilibrium assay
E. enzyme-linked immunosorbent assay
2. The following are the common substrates of horseradish peroxidase:
A. p-nitrophenyl phosphate
B. 4-methylumbelliferyl-R-D galactopyranoside
C. Hydrogen peroxide
D. o-phenylenediamine
E. Starch
3. The correct statement about the second stage of an immunoprecipitation reaction is that:
A. specific binding of the antigen-antibody
B .the reaction is rapid and can be completed in a few seconds to tens of seconds
C. the appearance of precipitation lines or precipitation rings visible to the naked eye
D. the appearance of small soluble complexes, which are not visible to the naked eye
4. The following is not a method of operation for flocculent precipitation experiments:
A. antigen dilution
B. antibody dilution
C. square Titration
D. Complex titration
5. The following experiments are not precipitation reactions:
A. Exofiltration test
B. Unidirectional diffusion test
C. Convective immunoelectrophoresis
D. Bidirectional diffusion test
6. Mancini curves are applicable to ________ the Results processing:
A. For results with large antigens and prolonged diffusion
B. For results with large antigens and shorter diffusion times
C. For results with small antigens and prolonged diffusion times
D. For results with small antigens and shorter diffusion times
Reference Answer vs. Analysis
1. Reference Answer A. Analysis: Enzyme amplification immunoassay technique and cloned enzyme donor immunoassay are homogeneous enzyme immunoassays. Equilibrium, non-equilibrium and ELISA are heterophasic enzyme immunoassays. Enzyme immunohistochemistry is an enzyme immunoassay.
2. Answer D. Analysis: Horseradish peroxidase (HRP) substrates include o-phenylenediamine (OPD) and tetramethylbenzidine (TMB), which is one of the most sensitive chromogenic substrates of HRP; OPD shows orange-yellow color in the presence of HRP, and brownish-yellow color after the termination of the reaction with reinforcement of acid.
3. Answer C. Analysis: There are two stages of precipitation reaction, the first stage is the specific binding of antigen and antibody, which can be completed in a few seconds to dozens of seconds, and the soluble small complexes appear, which are not visible to the naked eye; the second stage is the formation of visible immune complexes, which takes several minutes to several hours to complete, such as the precipitation line, the precipitation ring. This precipitation test is directly affected by the ratio of antigen to antibody, and is therefore commonly used as a basic assay for determining the optimal ratio of antigen-antibody reaction. There are three general types of operation: antigen dilution, antibody dilution, and square titration.
5. Reference answer A. Explanation: the external Fi test is an agglutination test, and the one-way diffusion test, convective immunoelectrophoresis, and two-way diffusion test are all precipitation reactions.
6.Answer A: Mancini curve is suitable for large molecule antigen and prolonged diffusion (> 48 hours); Fahey curve is suitable for small molecule antigen and shorter diffusion results processing. Therefore, the question is A.