Allergy Unit

**Semantic type:** Quantitative Concept

**Definition:** A biological potency unit assigned to several standardized allergenic extracts, following in-vitro comparison of the test extract to an FDA CBER reference standard. The FDA CBER reference standard may be assigned a specific AU unitage based on quantitative skin testing in allergic individuals, or based on specific allergen content.

**Synonyms:** - ALLERGY UNITS - AU - AU - AU - [AU] - [AU] - [AU] - [AU] - [AU] - [AU] - allergen unit - allergen unit - allergy unit