Opsonophagocytic Killing Assay

**Semantic type:** Laboratory Procedure

**Definition:** An assay to assess the opsonophagocytic killing activity of antibodies that measures the functionality of phagocytic immune cells by incubating different dilutions of co-cultured bacteria, sera, and complement, and then quantifying the percent bacterial survival of a single serotype relative to serum-negative controls.

**Synonyms:** - OPA - OPSONOPHAGOCYTIC KILLING ASSAY