Opsonization Index

**Semantic type:** Laboratory Procedure

**Definition:** A measurement that compares the phagocytic activity of an infected individual's blood for a particular microorganism to that of a normal person. The opsonic index is the ratio of the phagocytic index of infected or immune serum divided by the phagocytic index of normal serum.

**Synonyms:** - OI - OPSONIZATION INDEX - Opsonic Index