title: Activity units for allergen extracts.
abstract: The two present systems of units for the strength of allergen extracts, Noon and p.n.u. are both unsatisfactory. A new activity unit, based on skin prick in humans, is described, and its relationship to in vitro tests is explored. Potency limits for provocation materials used for skin prick tests are suggested.
mesh_terms: D000485:Allergens / Q000592:standards*; D006801:Humans; D007525:Isoelectric Focusing; D011852:Radioallergosorbent Test; D012015:Reference Standards; D012882:Skin Tests
chemical_list: D000485:Allergens