Fluoroimmunoassays for cannabinoids in urine.
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Cannabinoids↗
Biomedical subjects
D L Colbert
Publications and source records attributed to D L Colbert.
Multiple drugs of abuse in urine detected with a single reagent and fluorescence polarization.
We describe a simple polarization fluoroimmunoassay for the detection of several commonly abused drugs in urine. The single reagent used, prepared by mixing four different antisera and three fluorescein-labeled derivatives, produces a polarization signal that is the average of the individual signals of the derivatives. One adds urine to the pre-mixed reagent, incubates at room temperature for a few minutes, then measures fluorescence polarization. The presence of any of several abused drugs, at concentrations of 1 mg/L or more, noticeably decreases the average signal. Although other combinations are possible, the present assay detects the presence of a cocaine metabolite, amphetamine, and (or) several barbiturates.
Amphetamine↗
Single-reagent polarisation fluoroimmunoassay for the cocaine metabolite, benzoylecgonine, in urine.
A polarisation fluoroimmunoassay is described for the detection in urine of benzoylecgonine, the major metabolite of cocaine. The method uses a single reagent comprising sheep anti-benzoylecgonine serum pre-mixed with a fluorescein-labelled benzoylecgonine derivative as tracer. Under the assay conditions the antiserum has equal cross-reactivity with cocaine and the metabolite. The test is performed by the addition of 10 microL of urine to an aliquot of the single reagent, incubation for a few minutes and measurement of fluorescence polarisation. The assay has a positive/negative cut-off level of 1 mg/L benzoylecgonine and results compare favourably with the EMIT-d.a.u.TM (Syva) system.
Antibody Specificity↗
Single-reagent polarization fluoroimmunoassay for amphetamine in urine.
This simple polarization fluoroimmunoassay for detection of amphetamine in urine involves the use of a single reagent: suitably diluted antiserum plus fluorescein-labeled amphetamine as tracer. To this, one adds 10 microL of urine, incubates for a few minutes at room temperature, and measures the fluorescence polarization. By using an antiserum obtained against an immunogen conjugated via the para position of the drug's phenyl ring, we have attained greater specificity than that of most existing immunoassays. As little as 1 mg of amphetamine per liter was easily detected. Results for 266 patients' urines agreed completely with those by gas-liquid chromatography. When a nonseparation enzymoimmunoassay (EMIT-d.a.u., Syva) was applied to 62 specimens chosen without conscious bias, three results were falsely negative, three falsely positive.
Adult↗
Single-reagent polarization fluoroimmunoassay for barbiturates in urine.
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.
Barbiturates↗