WorksheetsOFFICIAL QUIZ 3-SEROLOGICAL PRINCIPLES
Total questions: 50
Worksheet time: 2hrs 40mins
Name
Class
Date
1.
Agglutination reactions involving IgG may need to be enhanced for which of the following reason?
a)
It is only active at 25°C.
b)
It has only one antigen-binding site.
c)
It may be too small to produce lattice formation.
d)
It is not able to produce visible in vitro agglutination.
2.
When soluble antigens diffuse in a gel that contains antibody, in which zone does optimum precipitation occur?
a)
Prozone
b)
Postzone
c)
Zone of inhibition
d)
Zone of equivalence
3.
Immunoassays are based on which of the following principles?
a)
Protein binding to isotopes
b)
Separation of bound and free analyte
c)
Production of antibodies against haptens
d)
Antibody recognition of homologous antigen
4.
Which of the following BEST describes serologic cross-reactions?
a)
It is detected only later than specific reactions.
b)
It results from external contamination of reagents.
c)
It is indicative of infection with an unrelated organism
d)
It usually has weaker reactions than specific reactions.
5.
Which of the following statements applies to the Fc fragment of an immunoglobulin molecule?
a)
It consist of the entire heavy chain
b)
It contains the variable region of the heavy chain
c)
It is the region of the molecule that binds to receptors on various white blood cells
d)
It contains the antigen binding sites of the molecule
6.
If cells are not centrifuged long enough in a tube agglutination procedure, which of the following will MOST likely occur?
a)
Invalid Result
b)
False-positive
c)
False-negative
d)
Slight effect but can be ignored
7.
Which of the following is MOST LIKELY to account for the failure of a visible antigen-antibody reaction?
a)
Serologic testing done at room temperature
b)
Excess antibody or antigen in sample/reagent mixture
c)
Incubation at 37C for suspected immune antibody
d)
Maintaining pH of 7.0 to 7.4 of sample/reagent mixture
8.
Which of the following BEST describes prozone phenomenon?
a)
Results from increased amount of antigen
b)
Results in a false positive serologic reaction
c)
Results in a false negative serologic reaction
d)
Corrected by repeat testing of blood specimen one or more weeks later to allow time for antibody production
9.
While performing a test for naturally occurring antibodies, the medical technologist heat inactivated the serum and utilized the sample for testing immediately. This action would MOST likely result in which of the following?
a)
Prozone reaction
b)
False negative result
c)
Hemolysis in the test reaction
d)
Normal test result
10.
All of the statements below regarding agglutination reactions used for serodiagnosis are true EXCEPT:
a)
Agglutination reactions are usually two-step processes involving sensitization and lattice formation
b)
Most reactions are direct that only detects agglutinating antibodies
c)
Both liquid-phase and solid-phase test systems can be applied
d)
Carrier particles for antigen may be latex, RBCs or yeast
11.
How is complement activity initially destroyed in vitro?
a)
Keep serum at room temperature of 22°C for 1 hour
b)
Heat serum at 56°C for 30 minutes
c)
Heat serum at 56°C for 10 minutes
d)
Heat serum at 37°C for 45 minutes
12.
What is the difference between agglutination and precipitation reactions?
a)
Agglutination occurs when the antigen is particulate
b)
Precipitation reaction occurs when the antigen is particulate
c)
Agglutination occurs between a soluble antigen and antibody
d)
Precipitation reaction occurs when both antigen and antibody are particulate
13.
What is the process wherein a reagent antiserum and a patient’s specimen are added to opposing wells in an agar plate and an electrical current is then applied to this plate?
a)
Rocket electrophoresis
b)
Immunoelectrophoresis
c)
Double immunodiffuson
d)
Counterimmunodiffusion
14.
What is the indicator system used in the complement fixation test?
a)
Antisera
b)
Guinea pig complement
c)
Sensitized sheep red blood cells
d)
Enzyme-labeled antihuman globulin
15.
Agglutination of dyed bacterial cells represents what type of reaction?
a)
Coagglutination
b)
Direct agglutination
c)
Passive agglutination
d)
Agglutination inhibition
16.
Which of the following tests is a lack of agglutination a positive reaction?
a)
Hemagglutination
b)
Complement fixation
c)
Passive agglutination
d)
Agglutination inhibition
17.
Which of the following correctly describes reverse passive agglutination?
a)
It can be used to detect autoantibodies.
b)
It is used for identification of bacterial antigens.
c)
It can be used to detect antibodies against viral antigens.
d)
It is used to detect antibody sensitization of red blood cells.
18.
Which of the following statements BEST describes competitive binding immunoassays?
a)
All the patient analyte is bound in the reaction.
b)
Excess binding sites for the analyte are provided.
c)
Labeled and unlabeled analyte are present in equal amounts.
d)
The concentration of patient analyte is inversely proportional to bound radioactive label.
19.
Which of the following technique is typically radial immunodiffusion combined with electrophoresis?
a)
Ouchterlony technique
b)
Rocket electrophoresis
c)
Immunoelectrohoresis
d)
Countercurrent electrophoresis
20.
Which of the following describes an antigen-antibody precipitation reaction of partial identity?
a)
Precipitin lines cross, forming double spurs
b)
Precipitin lines fuse, forming a single spur
c)
Precipitin lines fuse, forming a single arc
d)
No precipitin lines are formed
21.
Soluble immune complexes are formed under which of the following conditions of zonal phenomenon?
a)
Antibody excess
b)
Reagent excess
c)
Antigen excess
d)
Sample Excess
22.
Which of the following immunoassays must be employed to determine if a patient is allergic to a certain seafood like shrimp?
a)
Indirect radioimmunosorbent test
b)
Direct radioimmunosorbent test
c)
Competitive radioimmunoassay
d)
Radioallergosorbent test
23.
In an indirect ELISA method designed to detect antibody to “X” virus in patient serum, the labeled conjugate used should be composed of which of the following?
a)
Antihuman anti-X antibody conjugated to an enzyme
b)
X antigen conjugated to an enzyme
c)
Anti-X antibody conjugated to a substrate
d)
Anti-X antibody conjugated to an enzyme
24.
Agglutination inhibition could BEST be used for which of the following types of antigens?
a)
Large cellular antigens such as erythrocytes
b)
Antigen attached to latex particles
c)
Antibodies carried by bacteria
d)
Soluble haptens
25.
Which of the following enzyme immunoassay techniques is based on the creation of an active enzyme in the presence of patient antigen ligand since the reagent antibody was neutralized by patient sample and did not inhibit the assembly of the active enzyme?
a)
Cloned enzyme donor immunoassay
b)
Competitive enzyme-linked immunoassay
c)
Sandwich enzyme-multiplied immunoassay
d)
Enzyme-multiplied immunoassay technique
26.
Which of the following is TRUE regarding the radial immunodiffusion test?
a)
The area of precipitin ring indicates identity to the antibody in the sample
b)
The area of precipitin ring indicates non-identity to the antigen in the sample
c)
The area of the precipitin ring is directly proportional to the concentration of antigen in the sample.
d)
The area of the precipitin ring is directly proportional to the concentration of the antibody in the sample.
27.
In radial immunodiffusion test, the gel contains which of the following?
a)
Antibody
b)
Patient sample
c)
Antigen to be tested
d)
Agarose with polyacrylamide gel
28.
Which of the following BEST describes the difference between nephelometry and turbidimetry?
a)
Nephelometry is an updated modification of turbidimetry.
b)
There is no difference between nephelometry and turbidimetry, only in name.
c)
Nephelometry measures light transmitted through a solution, and turbidimetry measures light scattered in a solution.
d)
Nephelometry measures light scattered in a solution, and turbidimetry measures light transmitted through a solution.
29.
Which of the following is characteristic of the Mancini method of single radial diffusion?
a)
Concentration is directly in proportion to the area of the precipitin ring.
b)
Readings are taken before reaching the zone equivalence.
c)
The diameter is plotted against the log of the concentration.
d)
It is primarily a qualitative rather than a quantitative method.
30.
Which of the following is a major advantage of the ELISA versus the RIA procedure?
a)
A gamma counter is used for quantitation
b)
A radioactive waste disposal system is required
c)
The enzyme tag is attached to a radioactive label
d)
Enzyme labels are used instead of radioactive labels
31.
Which of the following antibodies can bind to killed Staphylococcal cells via protein A to detect antigens thru coagglutination?
a)
IgA
b)
IgD
c)
IgE
d)
IgG
32.
Which of the following BEST characterizes a capture or sandwich enzyme assay?
a)
Requires two wash steps
b)
Enzyme activity is inversely proportional to the concentration of the analyte
c)
Uses a limited number of antibody sites on solid phase
d)
Best for small antigens with a single determinant
33.
Which of the following does a high signal in a competitive radioimmunosorbent test suggest?
a)
The patient sample has a low concentration of IgE.
b)
The patient sample has a low concentration of IgM.
c)
The patient sample has a high concentration of IgE.
d)
The patient sample has a high concentration of IgM.
34.
Immunofixation electrophoresis differs from immunoelectrophoresis in which way?
a)
It is mainly used for antigen detection
b)
Electrophoresis takes place after diffusion has occurred.
c)
Better separation of proteins with the same electrophoretic mobilities is obtained.
d)
Antibodies incorporated in cellulose acetate membrane is directly applied onto the gel instead placing antibodies in a trough/well cut in the gel after electrophoresis
35.
What is the major bond formed between antigens and antibodies in a serologic reaction?
a)
Covalent bond
b)
Hydrophobic bond
c)
Hydrogen bond
d)
Electrostatic force
36.
Which one of the following describes a direct immunofluorescence assay?
a)
Conjugated reagent antibody reacts with antigen to form antigen-antibody complexes
b)
Antigens react with unlabeled antibody forming antigen-antibody complexes that attach to labeled antibodies
c)
A dye is attached to a molecule and it reacts with an immune complex to produce a color
d)
Conjugated reagent antigen reacts with antibodies to form antigen-antibody complexes
37.
Which of the following indirect labeled immunoassays shows very bright fluorescence?
a)
Indirect fluorescent immunoassay
b)
Biotin-avidin immunofluorescence
c)
Fluorescence polarization immunoassay
d)
Enzymme-linked immunosorbent spot test
38.
Which of the following methods has the highest analytical sensitivity?
a)
Immunoelectrophoresis
b)
Agglutination inhibition
c)
Immunofluorescence
d)
Radioimmunoassay
39.
Which of the following BEST characterizes chemiluminescent assays?
a)
Magnetic beads are used as chemical tags.
b)
These are only homogeneous assays.
c)
A chemical is oxidized to produce light.
d)
Only the antigen can be labeled.
40.
Which of the following methods is applied in the detection of antibodies only capable of coating red blood cell antigens but not cross-linking or bridging of immune complexes?
a)
Antihuman-globulin test
b)
Direct hemagglutination
c)
Passive hemagglutination
d)
Hemagglutination inhibition
41.
Which of the following describes an antigen-antibody reaction?
a)
The reaction is reversible
b)
A lattice is formed at prozone
c)
A lattice is formed at postzone
d)
The reaction involves covalent bonds
42.
Which outcome indicates a negative result in complement fixation test?
a)
Hemolysis
b)
Hemagglutination
c)
Absence of hemolysis
d)
Absence of hemagglutination
43.
Which of the following is TRUE of fluorescence polarization immunoassay?
a)
Both antigen and antibody are labeled and polarized.
b)
Large molecules polarize more light than smaller molecules.
c)
When binding occurs, fluorescence emitted by the tag will disappear after polarization.
d)
The amount of polarized fluorescence is directly proportional to concentration of the analyte.
44.
Which of the following BEST describes direct fluorescent assays?
a)
Antibody is attached to a solid phase.
b)
The reagent anti-immunoglobulin has the fluorescent tag.
c)
Microbial antigens can be rapidly identified by this method.
d)
The amount of fluorescence is inversely proportional to the amount of antigen present.
45.
When performing the enzyme-multiplied immunoassay technique, how is the ligand in the patient's serum detected?
a)
Binds to enzyme-labeled antibody
b)
Forms antibody-antigen complex and precipitates
c)
Agglutinates by binding to antibody coated latex beads
d)
Competes with enzyme-labeled antigen for binding to a specific antibody
46.
In a noncompetitive enzyme immunoassay, if a negative control shows the presence of color, which of the following is the MOST likely explanation?
a)
Washing steps were incomlete
b)
No reagent was added.
c)
Reagents were expired.
d)
No substrate was present.
47.
In an indirect immunofluorescent antibody test for detection of “X” virus antigens from patient sample, the reagent antibody conjugated with a fluorescent label shall be used to enhance visualization of which of the following?
a)
X virus conjugated to a fluorescent dye
b)
Reagent anti-X virus antibody
c)
Antihuman globulin conjugated to a substrate
d)
Antihuman globulin conjugated to a fluorescent dye
48.
The directions for a slide agglutination test instruct that after mixing the patient’s serum and latex particles, the slides must be rotated for 2 minutes before reading the results. What would happen if the slide were rotated for 10 minutes?
a)
No effect
b)
Agglutination shall be enhanced and is valid
c)
Possible false positive result shall be observed
d)
Possible false negative result shall be observed
49.
Which of the following BEST describes the serologic application of complement fixation tests?
a)
Complement fixation test can detect transplacental antibodies
b)
Complement fixation test can detect antibodies that marks convalescence from an infection
c)
Complement fixation test for antibodies is usually positive early in the course of the disease
d)
Complement fixation test is used in detecting coproantibodies secreted in the intestinal tract
50.
Which of the following methods is used in indirect ELISA tests for “X” antibody from patient sample?
a)
Binding of patient antibody to liquid-phase recombinant X antigens, followed by addition of enzymes-labeled antibodies and substrates then transferred to an agar plate for immune complex count
b)
Binding of patient antibody to solid-phase recombinant X antigens, followed by addition of enzyme-labeled antihuman immunoglobulin
c)
Binding of patient antibody to solid-phase recombinant X antigens, followed by addition of enzyme-labeled X-specific antibodies
d)
Binding of patient antibody to solid-phase recombinant X antigens, followed by addition of enzyme-labeled X antigens
100 %
