1.9: Immunology and Immunochemistry
- Page ID
- 38589
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- Which of the following describes the chemical characteristic of an antibody?
- carbohydrate
- lipid
- protein
- electrolyte
- ligand
- In quantitative immunoassays the single most important factor responsible for success or failure is:
- specificity
- affinity
- titer
- monoclonal property
- antibody absorption
- Immunonephelometry is based upon the principle that:
- antigen and antibody form complexes in antigen excess
- antigen and antibody react to form precipitin line
- antigen and antibody form small complexes in antibody excess
- antigen and antibody form large complexes which precipitate
- antigen and antibody form large lattice structures which precipitate
- Which of the following describes a sandwich fluoroimmunoassay?:
- reagent antibody (solid phase) + antigen in patient sample, incubate, + luoroscein labeled anti-antigen
- reagent antibody (solid phase) + antigen in patient sample, incubate, + fluoroscein labeled anti—antibody
- reagent antibody (solid phase) + antigen in patient sample, incubate, + fluoroscein labeled indicator antigen
- reagent antibody (solid phase) + antigen in patient sample + fluoroscein labeled antiantigen, incubate, + indicator antigen
- reagent antibody (solid phase) + indicator antigen, incubate, + fluoroscein labeled anti—antigen
- In double diffusion, immune precipitation reactions occur when two lines cross each other: The reaction is one of:
- antigen identity
- identity
- partial identity
- antibody identity
- non-identity
Use the following Key to answer Questions 6 – 24.
- 1,2, and 3 are correct
- 1 and 3 are correct
- 2 and 4 are correct
- only 4 is correct
- all are correct
- Which of these are precipitin based assays?
- Ouchterlony
- ELISA
- immunoelectrophoresis
- complement fixation
- Which of the following factors affects antigenicity?
- chemical nature
- size
- conformation
- genetics
- Which of the following describe the properties of an antibody?
- has H & L chain
- can be degraded into Fab and Fc fragments
- has V and C regions
- has J chain
- Antibody affinity describes:
- heterogeneity of antibody
- closeness of fit
- diversity of antibody
- the association constant
- Cross-reactivity
- usually involves low affinity antibodies
- is often found in crossed immunoelectrophoresis gels
- is often observed between similar antigenic determinants
- is the most important reaction in nephelometry
- Antigen-antibody precipitation reactions occur because:
- both molecules are multivalent in nature
- large complex lattices are formed
- antibody and antigen are at equivalence
- antigen is present in excess
- Radial imunodiffusion is a technique:
- which quantifies antigens
- which requires a mono-specific antibody solution
- which results in the formation of precipitin rings
- which measures antigen equivalence
- Antigens present in biological fluids are subject to degradation depending upon:
- nature of the antigen
- concentration
- stability to storage conditions
- susceptibility to enzymes
- Agglutination reactions are:
- dependent upon antigen bridging between antibody molecules
- dependent upon formation of antibody bridges between antigen particles
- dependent upon the positive charge of the latex bead
- usually best done using 1gM reactions
- Complement fixation assays:
- are more efficient with IgM than with IgG
- do not work with all classes of IgG
- make holes in the membranes of target cells
- results are read from aggregates of red cells
- Which of the following are indicator molecules for immunoassays?:
- enzymes
- fluorescing molecules
- radionuclide
- absorbing molecules
- Microtiter or ELISA readers:
- are spectrophotometers adapted to read small volumes
- can rapidly read 96 samples
- are spectrophotometers adapted to read titers
- are optical character readers for microtiter plates
- The Western Blot technique involves:
- electrophoresis of proteins in polyacrylamide or agarose
- transfer of separated proteins to nitrocellulose
- detection of individual species of proteins by immunoassay
- detection of very low levels of individual proteins
- The sandwich technique with labeled antibody that is used for antibody measurement:
- has three layers
- has two layers
- has antigen (1st layer), antibody (second layer), and second antibody with enzyme label (third layer)
- has antibody (1st layer) and second antibody with enzymelabel (second layer)
- Substances that are known to interfere with immunoassays are
- compounds that are chemically similar to the antigen
- sample matrix
- heterologous antibodies that react with the reagent antibody
- hemoglobin
- An heterogeneous, competitive binding immunoassay requires
- labeled antigen
- separation of the bound label
- excess antibody
- a large antigen with multiple binding sites
- A non-competitive immunoassay is characterized by
- sandwich formed between antigen and antibody
- possible high dose hook at high antigen concentrations
- not applicable to small molecules
- excess antibody reaction
- Which of the following are associated with nephelometric immunoassays?
- small immune complexes are formed by the unknown antigen and reagent antibody
- polyethylene glycol prevents complex formation
- light scatter is proportional to antigen concentration
- antigen excess
- Measures that can be instituted to improve specificity of an assay include
- purify the antiserum by absorption techniques
- use sandwich technology
- select an antibody which binds an unique epitope on the antigen
- use chemiluminescent molecules as label
- Answer
-
- c (p. 219)
- a (p. 230)
- c (p. 232-233)
- a (p. 239-241)
- e (p. 225)
- b (p. 225,231)
- e (p. 217-218)
- a (p. 219-220)
- c (p. 222)
- b (p. 222-223)
- a (p. 223-224)
- a (p. 225)
- e (p. 230-231)
- c (p. 234)
- a (p. 236-237)
- a (p. 238)
- b (p. 239-240)
- e (p. 231-232)
- b (p. 239)
- a (p. 229-231)
- a (p. 240)
- e (p. 239)
- b (p. 232-233)
- a (p. 229-231)