Practice question

Prozone phenomenon describes false negative due to overwhelming antibody concentration relative to antigen, disrupting optimal lattice formation required for visible precipitation or agglutination. Each antigen possesses multiple epitopes, and lattice requires alternating antigen-antibody bridging. When antibody is in great excess, individual antigen molecules become saturated with separate antibodies without interconnection, producing small soluble complexes instead of extended network. No macroscopic clumping appears despite strong immunity. Diluting serum restores equivalence zone and reveals true positivity. Antigen excess causing similar loss is termed postzone. Prozone is classic caveat in syphilis VDRL and Brucella diagnostics.