Deck 12: Labeling Techniques in Immunoassay

Question 1

Indirect immunofluorescent assay (IFA) is widely used for the detection of

A)autoantibodies.
B)antibody to tissue antigen.
C)antibody to cellular antigen.
D)All of the above.

Answer 1

All of the above.

Question 2

Chemiluminescence refers to

A)light emitted.
B)heat emitted.
C)a chemical reaction.
D)Both A and C.

Answer 2

Both A and C.

Question 3

In a changing clinical environment, the indirect immunofluorescent assay (IFA) has been replaced with the enzyme immunoassay (EIA). A disadvantage of this trade-off to EIA is

A)lower cost.
B)that it is slower in producing results.
C)that it is more technically challenging and requires more training and experience.
D)that it is problematic for patients with less than a 1:160 antinuclear antibody (ANA) titer.

Answer 3

that it is problematic for patients with less than a 1:160 antinuclear antibody (ANA) titer.

Question 4

Match the assays and definitions.
Direct immunofluorescent assay

A)Antibodies can act as antigens and react with anti-immunoglobulins.
B)Conjugated antibody is used to detect antigen-antibody reactions at a microscopic level.
C)An antigen is first exposed to unlabeled antibody and then to labeled antibody.

Question 5

Match the type of enzyme immunoassay (EIA) with the appropriate description.
Noncompetitive EIA

A)The amount of color that develops in the reaction is inversely proportional to the amount of antibody.
B)Antibody specific for immunoglobulin M (IgM) or IgG is attached to a solid-phase surface.
C)A specific antigen is attached to a solid-phase surface.

Question 6

Match the assays and definitions.
Indirect immunofluorescent assay

A)Antibodies can act as antigens and react with anti-immunoglobulins.
B)Conjugated antibody is used to detect antigen-antibody reactions at a microscopic level.
C)An antigen is first exposed to unlabeled antibody and then to labeled antibody.

Question 7

FISH technology

A)uses recombinant DNA technology.
B)detects hematopathologic chromosomal abnormalities.
C)detects oncogenic chromosomal abnormalities.
D)All of the above.

Question 8

An advantage of enzyme immunoassay (EIA) compared with radioimmunoassay (RIA) is

A)a longer shelf life.
B)no need for automation.
C)no radioactive hazardous waste.
D)decreased risk of transmission of infectious diseases.

Question 9

Match the chemiluminescent format with the appropriate description.
Competitive chemiluminescence

A)A fixed amount of labeled antigen competes with unlabeled antigen from a patient specimen for a limited number of antibody-binding sites.
B)The sample antigen binds to an antibody fixed onto a solid phase; a second antibody, labeled with a chemiluminescent label, binds to the antigen-antibody complex on the solid phase.
C)A fixed amount of labeled antibody competes with unlabeled antibody from a patient specimen for a limited number of antigen-binding sites.
D)The sample antibody binds to an antigen fixed onto a solid phase; a second antigen, labeled with a chemiluminescent label, binds to the antigen-antibody complex on the solid phase.

Question 10

Fluorescent molecules in immunofluorescent techniques are used as substitutes for

A)radioisotopes.
B)enzyme labels.
C)antibody substitutes.
D)Both A and B.

Question 11

Match the chemiluminescent format with the appropriate description.
Sandwich immunoassay

A)A fixed amount of labeled antigen competes with unlabeled antigen from a patient specimen for a limited number of antibody-binding sites.
B)The sample antigen binds to an antibody fixed onto a solid phase; a second antibody, labeled with a chemiluminescent label, binds to the antigen-antibody complex on the solid phase.
C)A fixed amount of labeled antibody competes with unlabeled antibody from a patient specimen for a limited number of antigen-binding sites.
D)The sample antibody binds to an antigen fixed onto a solid phase; a second antigen, labeled with a chemiluminescent label, binds to the antigen-antibody complex on the solid phase.

Question 12

Chemiluminescent enzyme labels often used in indirect procedures are

A)alkaline phosphatase.
B)horseradish peroxidase.
C)beta-galactosidase.
D)All of the above.

Question 13

Match the following emerging technology with the appropriate definition.
Fluorescent in situ hybridization (FISH)

A)Semiconductor nanocrystals
B)Method of tagging antibodies with superparamagnetic particles
C)Technology based on two different 200-nm latex particles
D)Molecular cytogenetic technique
E)May be used in many fluorescent and colorimetric applications

Question 14

Chemiluminescence

A)has excellent sensitivity and dynamic range.
B)does not require sample radiation.
C)uses unstable chemiluminescent reagents and conjugates.
D)Both A and B.

Question 15

Magnetic labeling application uses

A)automated DNA sequences.
B)DNA probe technology.
C)gel electrophoresis.
D)All of the above.

Question 16

Match the assays and definitions.
Inhibition immunofluorescent assay

A)Antibodies can act as antigens and react with anti-immunoglobulins.
B)Conjugated antibody is used to detect antigen-antibody reactions at a microscopic level.
C)An antigen is first exposed to unlabeled antibody and then to labeled antibody.

Question 17

To be used for enzyme immunoassay (EIA), an enzyme must exhibit

A)a high degree of stability.
B)extreme specificity.
C)absence from the antigen or antibody being tested.
D)All of the above.

Question 18

Match the type of enzyme immunoassay (EIA) with the appropriate description.
Capture EIA

A)The amount of color that develops in the reaction is inversely proportional to the amount of antibody.
B)Antibody specific for immunoglobulin M (IgM) or IgG is attached to a solid-phase surface.
C)A specific antigen is attached to a solid-phase surface.

Question 19

Match the type of enzyme immunoassay (EIA) with the appropriate description.
Competitive EIA

A)The amount of color that develops in the reaction is inversely proportional to the amount of antibody.
B)Antibody specific for immunoglobulin M (IgM) or IgG is attached to a solid-phase surface.
C)A specific antigen is attached to a solid-phase surface.

Question 20

The serologic method most widely used for the detection of diverse antibodies is

A)the direct immunofluorescent assay.
B)the inhibition immunofluorescent assay.
C)the indirect immunofluorescent assay.
D)None of the above.

Question 21

When using a fluorescent substance or dye, the color of the emitted light depends on the nature of the substance.

Question 22

In fluorescent antibody microscopy using a fluorescent substance or dye, the incident light is infrared.

Question 23

Match the following emerging technology with the appropriate definition.
Signal amplification technology

A)Semiconductor nanocrystals
B)Method of tagging antibodies with superparamagnetic particles
C)Technology based on two different 200-nm latex particles
D)Molecular cytogenetic technique
E)May be used in many fluorescent and colorimetric applications

Question 24

A fluorescent substance or dye absorbs light of one wavelength and emits light of another wavelength.