A sensitive ELISA for 6β-hydroxycortisol in urine using enzyme penicillinase (β-lactamase)

Abstract A sensitive and specific, enzyme labelled immunosorbent assay (ELISA) for 6β-hydroxycortisol in diluted urine using penicillinase was developed. 6β-Hydroxycortisol-21-hemisuccinate was conjugated with enzyme penicillinase. Antibody immobilized on a polyvinylchloride ELISA plate (Dynatech) was used for separation of bound from free ligand. The sensitivity of the assay was between 2.0–3.0 pg per well and recovery of 6β-hydroxycortisol from urine ranged between 85.0–108.0%. The assay is simple, rapid and precise.