Immunology & Serology Flashcards
7 cards from real CMLA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Immunology & Serology flashcards as text
What principle does the ELISA (Enzyme-Linked Immunosorbent Assay) use to detect antibodies or antigens?
Answer: Enzyme-labeled antibodies producing a colorimetric signal
ELISA uses enzyme-conjugated antibodies that catalyze a substrate reaction, producing a measurable color change proportional to antigen or antibody concentration.
In serological testing, agglutination indicates:
Answer: Cross-linking of particulate antigens by antibodies causing visible clumping
Agglutination occurs when antibodies form bridges between multiple particulate antigens (bacteria, red blood cells), causing visible clumping.
What is the purpose of including a positive control in a serological assay?
Answer: To verify the test system produces a positive result with known positive material
A positive control confirms the assay is functioning correctly by demonstrating it can produce the expected positive result with a known positive specimen.
In indirect fluorescent antibody (IFA) testing, the fluorescent-labeled secondary antibody binds to:
Answer: The patient's primary antibody already bound to antigen
In IFA, the fluorescent secondary antibody binds to the patient's (primary) antibody, which is already complexed with the antigen on the substrate.
What does a serum antibody titer measure?
Answer: The highest dilution of serum still showing a positive reaction
A titer is the reciprocal of the highest serum dilution that still yields a detectable (positive) reaction, reflecting relative antibody concentration.
Which non-treponemal test is used as a screening test for syphilis?
Answer: RPR (Rapid Plasma Reagin)
The RPR is a non-treponemal flocculation test that detects reagin antibodies against cardiolipin-lecithin-cholesterol antigen, used for syphilis screening.
In a precipitation reaction, the zone of equivalence refers to:
Answer: The point where antigen and antibody concentrations allow maximum lattice formation and precipitation
The zone of equivalence is where antigen and antibody are in optimal proportions, forming large cross-linked lattices that precipitate out of solution.