Question

question 20
a serum titer involves______.
a quantifying the number of infectious particles in a specimen
b determining the highest dilution of serum that produces a visible reaction
c determining the lowest dilution of serum that produces a visible reaction
d the western blot method

Explanation:

A serum titer measures antibody levels by diluting serum. The titer is defined as the highest dilution (most dilute) where a visible reaction (e.g., agglutination) still occurs. Option A is incorrect because it refers to counting infectious particles, not antibody levels. Option C is wrong as it mentions the lowest dilution (least dilute), which is not the titer. Option D is incorrect because Western blot is a different technique for detecting specific proteins, not a titer method.

Answer:

B. determining the highest dilution of serum that produces a visible reaction