Question 1

FISH technology:

Accepted Answer

Fluorescent in situ hybridization (FISH)uses fluorescent molecules to color genes or chromosomes brightly.The FISH molecular cytogenetic technique uses recombinant DNA technology.Clinical applications of FISH in the detection of inherited and acquired chromosomal abnormalities include hematopathology and oncology.Many genetic syndromes have been recognized by geneticists,but laboratory tests often are unavailable for confirmation.

Question 2

Match the assays and definitions.

-Direct immunofluorescent assay

Accepted Answer

Direct immunofluorescence involves the use of antibodies that are directly conjugated to a fluorescent dye, allowing for the visualization of antigen-antibody reactions under a microscope.

Question 3

Match the chemiluminescent format with the appropriate description.

-Sandwich immunoassay

Accepted Answer

In sandwich immunoassay, the sample antigen binds to an antibody fixed onto a solid phase, and a second antibody, labeled with a chemiluminescent label, binds to the antigen-antibody complex on the solid phase. This format is used to detect the presence and quantity of specific antigens. The other options (A, C, and D) correspond to competitive immunoassay formats, which involve competition between labeled and unlabeled antigens or antibodies for a limited number of binding sites.

Question 4

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

Accepted Answer

Capture EIA involves attaching an antibody specific for a particular immunoglobulin (e.g., IgM or IgG) to a solid-phase surface to "capture" the target antibodies from the sample.

Question 5

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:

Accepted Answer

An example of a changing clinical situation is that many laboratories have replaced the indirect immunofluorescence assay,once the standard for ANA testing,with EIA.Less labor and technical experience are cited as reasons for switching from IFA.However,the trade-off may not be valuable if patients have ANA titers lower than 1:160.

Question 6

Fluorescent molecules in immunofluorescent techniques are used as substitutes for:

Accepted Answer

Fluorescent molecules are used as substitutes for radioisotopes or enzyme labels.

Question 7

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

Accepted Answer

The serologic method most widely used for the detection of diverse antibodies is the indirect immunofluorescent assay (IFA).

Question 8

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

Accepted Answer

The EIA method uses a nonisotopic label that offers the advantage of safety compared with RIA.

Question 9

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

Accepted Answer

When absorbing light of one wavelength,a fluorescent substance emits light of another (longer)wavelength.In fluorescent antibody (FA)microscopy,the incident or exciting light is often blue-green to ultraviolet.The light is provided by a high-pressure mercury arc lamp with a primary (e.g. ,blue-violet)filter between the lamp and object that passes only fluorescein-exciting wavelengths.The color of the emitted light depends on the nature of the substance.Fluorescein gives off yellow-green light,and the rhodamines fluoresce in the red portion of the spectrum.The color observed in the fluorescent microscope depends on the secondary or barrier filter used in the eyepiece.A yellow filter absorbs the green fluorescence of fluorescein and transmits only yellow.Fluorescein fluoresces an intense apple green color when excited.

Question 10

Chemiluminescent enzyme labels often used in indirect procedures are:

Accepted Answer

Enzymes are typically used for indirect labels.Indirect labels are attached to antibodies,antigens,and DNA probes,depending on the assay format.Enzyme labels often used in indirect procedures include the following:
Alkaline phosphatase (ALP)
Horseradish peroxidase (HRP)
Beta-galactosidase (b-galactosidase)

Question 11

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

Accepted Answer

Immunofluorescence is used extensively in the detection of autoantibodies and antibodies to tissue and cellular antigens.The following are examples of immunologic assays performed by the IFA technique:
Antiadrenal antibodies
Antibody (HR-ANA)
Anticentriole antibodies
Anticentromere antibodies
Anti-glomerular basement membrane antibodies
Anti-islet cell antibodies
Anti-liver-kidney microsomal (LKM)antibodies
Antimitochondrial
Antimyelin
Antimyocardial
Antinuclear antibody (ANA)
Anti-parietal cell
Antiplatelet
Antireticulin
Antiribosome
Antiskin (dermal,epidermal)
Antiskin (interepithelial)
Anti-smooth muscle
Antistriational
Cytomegalovirus (IgM antibody)
Histone-reactive antinuclear antibody (HR-ANA)
Human immunodeficiency virus (total and IgM antibody)
Immunoglobulin M (IgM)antibodies (antigen-specific)
Lymphocyte typing
Rubella virus antibody
Toxoplasma gondii antibody

Question 12

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

Accepted Answer

When absorbing light of one wavelength,a fluorescent substance emits light of another (longer)wavelength.In fluorescent antibody (FA)microscopy,the incident or exciting light is often blue-green to ultraviolet.The light is provided by a high-pressure mercury arc lamp with a primary (e.g. ,blue-violet)filter between the lamp and object that passes only fluorescein-exciting wavelengths.The color of the emitted light depends on the nature of the substance.Fluorescein gives off yellow-green light,and the rhodamines fluoresce in the red portion of the spectrum.The color observed in the fluorescent microscope depends on the secondary or barrier filter used in the eyepiece.A yellow filter absorbs the green fluorescence of fluorescein and transmits only yellow.Fluorescein fluoresces an intense apple-green color when excited.

Question 13

Magnetic labeling application uses:

Accepted Answer

Magnetic labeling technology is an application of the high-resolution magnetic recording technology developed for the computer disk drive industry.Increased density of microscopic,magnetically labeled biologic samples (e.g. ,nucleic acid on a biochip)translates directly into reduced sample-processing times.Magnetic labeling can be applied to automated DNA sequences,DNA probe technology,and gel electrophoresis.

Question 14

Chemiluminescence refers to:

Accepted Answer

Chemiluminescence refers to light emission produced during a chemical reaction and is used extensively in automated immunoassays.

Question 15

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

Accepted Answer

In a competitive EIA, the amount of color developed is inversely proportional to the amount of antibody present because both the sample antibody and a labeled antibody compete for binding sites on a specific antigen.

Question 16

Chemiluminescence:

Accepted Answer

Chemiluminescence has excellent sensitivity and dynamic range.It does not require sample radiation,and nonselective excitation and source instability are eliminated.Most chemiluminescent reagents and conjugates are stable and relatively nontoxic.

Question 17

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

Accepted Answer

When absorbing light of one wavelength,a fluorescent substance emits light of another (longer)wavelength.In fluorescent antibody (FA)microscopy,the incident or exciting light is often blue-green to ultraviolet.The light is provided by a high-pressure mercury arc lamp with a primary (e.g. ,blue-violet)filter between the lamp and object that passes only fluorescein-exciting wavelengths.The color of the emitted light depends on the nature of the substance.Fluorescein gives off yellow-green light,and the rhodamines fluoresce in the red portion of the spectrum.The color observed in the fluorescent microscope depends on the secondary or barrier filter used in the eyepiece.A yellow filter absorbs the green fluorescence of fluorescein and transmits only yellow.Fluorescein fluoresces an intense apple-green color when excited.

Question 18

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

Accepted Answer

The answer of Match the type of enzyme immunoassay (EIA)with...

Question 19

Match the chemiluminescent format with the appropriate description.

-Competitive chemiluminescence

Accepted Answer

A competitive chemiluminescence assay involves a competition between labeled and unlabeled antigen for antibody-binding sites, as described in option A.

Question 20

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

Accepted Answer

Various enzymes are used in EIA.Common enzyme labels are horseradish peroxidase,alkaline phosphatase,glucose-6-phosphate dehydrogenase,and beta-galactosidase.To be used in EIA,an enzyme must fulfill the following criteria:
High degree of stability
Extreme specificity
Absence from the antigen or antibody
No alteration by inhibitor with the system

Quiz 12: Labeling Techniques in Immunoassay

FISH technology:

Match the assays and definitions. -Direct immunofluorescent assay

Match the chemiluminescent format with the appropriate description. -Sandwich immunoassay

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

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:

Fluorescent molecules in immunofluorescent techniques are used as substitutes for:

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

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

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

Chemiluminescent enzyme labels often used in indirect procedures are:

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

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

Magnetic labeling application uses:

Chemiluminescence refers to:

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

Chemiluminescence:

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

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

Match the chemiluminescent format with the appropriate description. -Competitive chemiluminescence

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