Which Property of Antibodies is the Basis for Complement Fixation

Question

Which property of antibodies is the basis for complement fixation tests?
A) agglutination
B) opsonization
C) neutralization
D) direct killing
E) complement activation

Accepted Answer

Complement fixation tests rely on the activation of the complement system by antibodies. The binding of an antibody to its antigen triggers the classical pathway of the complement system, leading to the production of complement components that can eventually lyse target cells. The complement fixation test measures the ability of an antibody to trigger this pathway and fix complement.