Single-reagent polarisation fluoroimmunoassay for cotinine (a nicotine metabolite) in urine

Abstract

A rapid, single-reagent, non-separation, non-isotopic immunoassay was developed for determining levels of the nicotine metabolite, cotinine, in urine. The single reagent was prepared by pre-mixing an appropriate dilution of sheep anti-cotinine serum with a fluorescein-labeled cotinine tracer. All normal reliability criteria were satisfied. The assay was found to be specific for cotinine and there was no cross reactivity with other available nicotine metabolites and structurally-related compounds. The results obtained correlated closely with those of an established radioimmunoassay. The assay was well-suited to application in the discrimination of active smokers from non-smokers (and passive smokers).