Rapid Enzyme-Linked Immunosorbent Assay (ELISA) with a visual end-point for detecting opiate narcotics in urine

Abstract

A simple ELISA technique has been developed for detecting opiate narcotics in urine. The assay employs a visual end-point and has a limit of sensitivity of 3 µg l^–1 using 5-µl samples. No cross-reactivity is observed with non-opiate drugs commonly found in urine. The assay was used to identify opiates in urine from 38 addicts that had been screened using Toxi-Lab, EMIT and radioimmunoassay techniques. Only one false negative result was observed using the ELISA method. The assay may find application as an alternative to current screens where no sophisticated equipment is available for end-point detection.