Detection of D,L-Amphetamine, D,L-Methamphetamine, and Illicit Amphetamine Analogs Using Diagnostic Products Corporation's Amphetamine and Methamphetamine Radioimmunoassay*

Cross-reactivity with Diagnostic Products Corporation (DPC) amphetamine and methamphetamine radioimmunoassay (RIA) reagents was determined for amphetamine, methamphetamine, and a number of amphetamine analogs. Concentrations from 100 to 100,000 ng/mL were assayed. 3,4-Methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) showed significant cross-reactivity for the amphetamine and methamphetamine reagents respectively. 4-Hydroxymethamphetamine, 3,4-methylenedioxyethylamphetamine (MDEA), and N,N-dimethyl-MDA also showed significant cross-reactivity with the methamphetamine reagents, but less than MDMA. None of the other analogs showed a positive result with the amphetamine or methamphetamine reagents at even the highest concentration, although several did show measurable cross-reactivity. The L isomers of amphetamine and methamphetamine showed substantially less cross-reactivity than the D forms to which the respective antibody systems are targeted.