Deck 10: Laboratory Approaches to Serology Testing

Question 1

Which of the following assays would be useful in distinguishing between recent primary infection and later secondary immune response?

A)ELISA
B)Western blot
C)hemagglutinin inhibition
D)indirect fluorescent antibody

Answer 1

ELISA

Question 2

The standard laboratory screening test for HIV is _____, and the most widely used confirmation test for HIV is the ______.

A)ELISA, Western blot
B)ELISA, dark-field microscopy
C)complement fixation, Western blot
D)complement fixation, dark-field microscopy

Answer 2

ELISA, Western blot

Question 3

The specimen of choice in serological testing is ______.If the specimen is to be stored for 1 week prior to analysis, the specimen should be ______.

A)serum, frozen at -20°C
B)plasma, frozen at -20°C
C)serum, refrigerated
D)plasma, refrigerated

Answer 3

serum, frozen at -20°C

Question 4

Suppose a serum VDRL gave a positive result, and CSF showed 8 nucleated cells/mm³.What follow up test should be used in the laboratory diagnosis of neurosyphilis if the CSF VDRL tested positive, and what follow-up test should be used in the laboratory diagnosis of neurosyphilis if the CSF VDRL tested negative?

A)T.pallidum particle agglutination test, no follow-up testing is required
B)fluorescent treponemal antibody test, no follow-up testing is required
C)no follow-up testing is required, T.pallidum particle agglutination test
D)no follow-up testing is required, fluorescent treponemal antibody test

Question 5

Which immunoglobulin is primarily associated with allergic reactions?

A)IgG
B)IgM
C)IgA
D)IgE

Question 6

The TORCH acronym represents:

A)a series of progressive laboratory tests to identify HIV antibody isotypes
B)a group of pathogens that pose the greatest risk to a developing fetus
C)cellular membrane antigens to which antibodies are directed in Lyme disease
D)the order of reagent addition to prepare a sample for fluorescent-labeled microscopy

Question 7

The classic technique used in the laboratory for detection of the Epstein-Barr virus is the:

A)hemagglutinin inhibition test
B)complement fixation test
C)temperature solubility test
D)heterophile antibody test

Question 8

The difference between treponemal and non-treponemal serological tests for the laboratory detection of syphilis is based on:

A)the stage of syphilis (primary versus latent)
B)the antigen specificity tested
C)the specimen tested
D)the causative bacteria

Question 9

Which immunoglobulin will dominate the later portion of the primary immune response and subsequent amnestic response?

A)IgG
B)IgM
C)IgA
D)IgE

Question 10

Laboratory diagnosis of this disease is based on a two-tiered approach, with initial screening by IFA or ELISA and confirmation by Western blot.It is important that testing evaluate for IgM and IgG in order to increase chances of detecting and identifying this disease.

A)HIV
B)syphilis
C)herpes
D)Lyme disease

Question 11

Detection of which immunoglobulin implies recent antigen exposure?

A)IgG
B)IgM
C)IgA
D)IgE

Question 12

Which of the following clinical laboratory techniques is most commonly used to identify HIV and Lyme disease infections?

A)ELISA
B)Western blot
C)hemagglutinin inhibition
D)indirect fluorescent antibody

Question 13

Laboratory detection of T.pallidum can occur by:

A)direct detection by typical microscopic examination
B)direct isolation by culture under standard laboratory conditions
C)serological testing
D)all of the above

Question 14

A hemagglutinin inhibition (HAI) assay is a type of neutralization assay that demonstrates the presence of antibody by interference with a pathogenic mechanism.Although use of HAI assays is decreasing, this technique remains the gold standard for serotyping:

A)Treponema pallidum
B)influenza virus
C)Coccidioides
D)Histoplasma

Question 15

Select the causative agent for the following diseases: peptic ulcer, syphilis, herpes, Lyme disease.

A)Treponema pallidum, Borrelia burgdorferi, Helicobacter pylori, Epstein-Barr virus
B)B.burgdorferi, Epstein-Barr virus, T.pallidum, H.pylori
C)H.pylori, T.pallidum, Epstein-Barr virus, B.burgdorferi
D)Epstein-Barr virus, H.pylori, B.burgdorferi, T.pallidum

Question 16

Indirect fluorescent antibody (IFA) techniques measure ______ in the patient sample, using fluorescent ______.

A)antigen, spectrophotometry
B)antibody, spectrophotometry
C)antigen, microscopy
D)antibody, microscopy

Question 17

Serological testing is typically not the method of choice for this disease.

A)syphilis
B)Lyme disease
C)peptic ulcer
D)herpes

Question 18

Flocculation and precipitation agglutination reactions differ by:

A)Flocculation reactions result from the detection of antibody, and precipitation reactions result from the detection of antigen.
B)Flocculation reactions result from the detection of antigen, and precipitation reactions result from the detection of antibody.
C)Flocculation-reaction complexes float in solution, and precipitation-reaction complexes settle to the bottom of the solution.
D)Flocculation-reaction complexes can only be observed microscopically, and precipitation-reaction complexes can be observed macroscopically.

Question 19

Multiplex serological assays are techniques that measure multiple antibody specificities in a single assay.The basic concept for these assays is a ______ assay that is read by ______.

A)inhibition, nephelometry
B)sandwich, nephelometry
C)inhibition, flow cytometry
D)sandwich, flow cytometry

Question 20

Agglutination reactions are used to demonstrate the presence of ______.The prozone phenomenon is a ______ reaction that occurs when the concentration of this immune component is too high.

A)antigen, false-positive
B)antibody, false-positive
C)antigen, false-negative
D)antigen, false-negative.