title: Evaluation of TDx cocaine metabolite assay.
abstract: The TDx cocaine metabolite fluorescence polarization immunoassay (Abbott Laboratories) for the detection of benzoylecgonine (BE) in urine was evaluated. The threshold concentration for BE detection was 0.3 mg/L. The within- and between-run precision of the assay gave coefficients of variation less than 2.3% and 3.5%, respectively. One hundred twenty clinic urines positive for BE by high-pressure liquid chromatography (HPLC) were analyzed by the TDx and EMIT-dau cocaine metabolite assays. All three methods were positive for BE in 116 samples, 96.7%. Two samples were positive by TDx and negative by EMIT-dau, and two samples were positive by EMIT-dau and negative by TDx. Cocaine and ecgonine methyl ester cross reactivity with the TDx assay was less than 2%. One hundred drugs and drug metabolites were added to drug-free urine resulting in no false positive reactions. The same drugs and drug metabolites were also added to urine with 3.0 mg/L BE and analyzed by the TDx. No false positive reactions or inhibition of BE detection occurred.
authors: Department of Pathology, St. Louis University School of Medicine, Missouri 63104.
authors: A
authors: A
authors: Poklis
mesh_terms: D003042:Cocaine / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000652:urine; D003951:Diagnostic Errors; D005069:Evaluation Studies as Topic; D005454:Fluorescence Polarization; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D019966:Substance-Related Disorders / Q000652:urine*
chemical_list: C005618:benzoylecgonine; D003042:Cocaine