CLONED ENZYME DONOR IMMUNOASSAY (CEDIA) FOR DRUGS-OF-ABUSE SCREENING

Large numbers of specimens (5000-18 000) were screened for amphetamine s, barbiturates, cocaine, marijuana, opiates, and phencyclidine by RIA (Roche), Emit II (Syva), and a new immunoassay, CEDIA (cloned enzyme donor immunoassay, Microgenics). All immunoassays performed equivalent ly for cocaine, opiates, and phencyclidine. All immunoassays detected the same amphetamine/methamphetamine-positive specimens, but all also detected numerous specimens containing cross-reacting sympathomimetic amines. CEDIA detected 100%, Emit II 93%, and RIA 82% of the barbitura te-positive specimens. Emit II and CEDIA detected 86-88% of the specim ens found by RIA to be marijuana positive. A subset of specimens was a dditionally screened by Online (Roche) and TDx (Abbott) for amphetamin es, cocaine, and marijuana. Online and TDx also detected all of the am phetamine-positive specimens and numerous specimens containing cross-r eacting sympathomimetic amines. All immunoassays performed equivalentl y for cocaine, and the four nonisotopic tests detected 86-89% of the m arijuana positives found by RIA. Interfering sympathomimetic amine dru g compounds can be eliminated by using an oxidizing agent, thus decrea sing the number of unconfirmable amphetamine presumptive positives. Th e CEDIAs for all of the major drugs of abuse are reliable and effectiv e for large-volume urine screening programs.