title: Single-reagent polarization fluoroimmunoassay for barbiturates in urine.
abstract: We describe a rapid polarization fluoroimmunoassay for screening for the presence of barbiturates in urine. The single reagent is prepared by pre-mixing antiserum with a fluorescein-labeled barbiturate derivative as tracer. Use of a mixture of two sheep antisera, raised against different barbiturate immunogens, results in an assay with a broad cross-reactivity spectrum for most common barbiturates. One adds urine to the pre-mixed reagent, incubates the solution for a few minutes at room temperature, and measures the fluorescence polarization. The tracer/antiserum reagent is stable for at least six months at 4 degrees C. Results compare favorably with two other commonly used screening techniques for barbiturates, thin-layer chromatography and the EMIT-stTM (Syva) system. Although designed as a qualitative screen, some drugs can be quantified by means of a standard curve of the relevant barbiturate.
mesh_terms: D001463:Barbiturates / Q000652:urine*; D002855:Chromatography, Thin Layer; D003429:Cross Reactions; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D005454:Fluorescence Polarization; D005455:Fluorescent Antibody Technique; D006801:Humans; D007106:Immune Sera; D007124:Immunoenzyme Techniques; D007202:Indicators and Reagents; D007700:Kinetics; D010634:Phenobarbital / Q000276:immunology; D013861:Thiocyanates
chemical_list: D001463:Barbiturates; D005452:Fluoresceins; D007106:Immune Sera; D007202:Indicators and Reagents; D013861:Thiocyanates; D016650:Fluorescein-5-isothiocyanate; D010634:Phenobarbital