Medical Laboratory Technician Exam FREE Medical Laboratory Technician Immunology and Serology Questions and Answers 2

Question 1

Which immunoglobulin class is most abundant in serum and provides the majority of antibody-based immunity against invading pathogens?

Accepted Answer

IgG

Answer

IgM

Answer

IgA

Answer

IgE

Question 2

In a direct antiglobulin test (DAT), what does a positive result indicate?

Accepted Answer

Antibodies or complement are bound to the surface of red blood cells in vivo

Answer

Free antibodies are present in the patient's serum

Answer

The patient has an active bacterial infection

Answer

Complement levels are critically low

Question 3

Which complement pathway is activated by antigen-antibody complexes involving IgG or IgM?

Accepted Answer

Classical pathway

Answer

Alternative pathway

Answer

Lectin pathway

Answer

Terminal pathway

Question 4

A patient presents with recurrent Neisseria infections. Which complement component deficiency is most likely?

Accepted Answer

C5-C9 (membrane attack complex)

Answer

C1 esterase inhibitor

Answer

C3

Answer

Factor B

Question 5

What is the principle behind nephelometry as used in clinical immunology laboratories?

Accepted Answer

Measurement of light scattered by antigen-antibody complexes in solution

Answer

Measurement of light absorbed by colored enzyme substrates

Answer

Detection of fluorescent-labeled antibodies on cell surfaces

Answer

Quantification of radioactive isotope decay from labeled antigens

Question 6

Which serological test is considered the confirmatory test for HIV infection after a reactive screening immunoassay?

Accepted Answer

HIV-1/HIV-2 antibody differentiation immunoassay

Answer

Western blot only

Answer

Rapid plasma reagin (RPR)

Answer

Monospot test