1. A Sensitive Solid-Phase Fluoroimmunoassay for Detection of Opiates in Urine
- Author
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M. Bangalore, Kevin P. O'Connell, Nehad Azer, Jeremy Wright, Mohyee E. Eldefrawi, Robert P. Schwartz, Nabil A. Anis, and Nidhi Nath
- Subjects
Narcotics ,Metabolite ,Fluoroimmunoassay ,Bioengineering ,Urine ,Binding, Competitive ,Sensitivity and Specificity ,Applied Microbiology and Biotechnology ,Biochemistry ,chemistry.chemical_compound ,medicine ,Humans ,Molecular Biology ,Enzyme multiplied immunoassay technique ,Morphine Derivatives ,Autoanalysis ,Chromatography ,Morphine ,medicine.diagnostic_test ,Codeine ,Chemistry ,Antibodies, Monoclonal ,General Medicine ,Microspheres ,Benzoylecgonine ,Fluorescein ,Opiate ,Hapten ,Oxycodone ,Biotechnology ,medicine.drug - Abstract
An automated flow fluorometer designed for kinetic binding analysis was adapted to develop a solid-phase competitive fluoroimmunoassay for urinalysis of opiates. The solid phase consisted of polymer beads coated with commercial monoclonal antibodies (MAbs) raised against morphine. Fluorescein-conjugated morphine (FL-MOR) was used as the fluorescein-labeled hapten. The dissociation equilibrium constant (K D ) for the binding of FL-MOR to the anti-MOR MAb was 0.23 nM. The binding of FL-MOR to the anti-MOR MAb reached steady state within minutes and was displaced effectively by morphine and other opiates. Morphine-3-glucuronide (M3G), the major urinary metabolite of heroin and morphine, competed effectively with FL-MOR in a concentration-dependent manner for binding to the antimorphine MAb and was therefore used to construct the calibration curve. The sensitivity of the assay was 0.2 ng/mL for M3G. The assay was effective at concentrations of M3G from 0.2 to 50 ng/mL, with an IC50 of 2 ng/mL. Other opiates and heroin metabolites that showed >50% crossreactivity when present at 1 µg/mL included codeine, morphine-6-glucuronide, and oxycodone. Methadone showed very low crossreactivity (
- Published
- 2000
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