Estriol-specific antibody for steroid assays

Abstract Purified azobenzoyl estriol antibody IgG reacts specifically with native estriol. Fluorescence quenching of IgG by derivatized steroids provided experimentally determined binding constants over a wide range of concentrations. Since functional hydroxyl groups on the immunogen had been unmolested during synthesis, it was possible to isolate an antibody population which did not cross-react significantly with related estratrienes.