Medical Laboratory Technician Exam FREE Medical Laboratory Technician Immunology and Serology Questions and Answers 3

Question 1

Which type of hypersensitivity reaction is responsible for hemolytic disease of the fetus and newborn (HDFN)?

Accepted Answer

Type II (cytotoxic)

Answer

HDFN is a Type II hypersensitivity reaction in which maternal IgG antibodies cross the placenta and destroy fetal red blood cells.

Question 2

What is the purpose of adding anti-human globulin (AHG) reagent in the indirect antiglobulin test (IAT)?

Accepted Answer

To detect IgG antibodies that have bound to red blood cells during in vitro incubation

Answer

AHG crosslinks IgG molecules coating the red blood cells, causing visible agglutination that confirms antibody binding during incubation.

Question 3

A laboratory performs a fluorescent treponemal antibody absorption (FTA-ABS) test. This test is classified as which type of syphilis test?

Accepted Answer

Treponemal confirmatory test

Answer

FTA-ABS is a treponemal test that detects specific antibodies against Treponema pallidum and is used to confirm reactive non-treponemal screening results.

Question 4

In flow cytometry, what is the function of the forward scatter (FSC) detector?

Accepted Answer

To measure relative cell size

Answer

Forward scatter is proportional to cell size, allowing differentiation of cell populations based on their relative dimensions.

Question 5

Which autoantibody is most specific for systemic lupus erythematosus (SLE)?

Accepted Answer

Anti-double-stranded DNA (anti-dsDNA)

Answer

Anti-dsDNA antibodies are highly specific for SLE and their titers often correlate with disease activity, particularly lupus nephritis.

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Medical Laboratory Technician Exam Practice Test

Medical Laboratory Technician Exam FREE Medical Laboratory Technician Immunology and Serology Questions and Answers 3