Multiplex assay of amphetamine, methamphetamine, and ecstasy drug using CEDIA technology.

Abstract

Using Microgenics unique technology, cloned enzyme donor immunoassay (CEDIA), the multiplex assay (CEDIA Amphetamines/Ecstasy) has been developed for the detection of amphetamine, methamphetamine, and ecstasy drugs at cutoff level either of 500 ng/mL or 1000 ng/mL applicable for either qualitative screening or semiquantitative measurement. The multiplex assay detects the total concentration of amphetamine, methamphetamine, and ecstasy drugs in urine samples. In addition, the assay detects metabolites of parent drugs and structurally related drugs including d,l-amphetamine (67.2%), d,l-methamphetamine (58.4%), MDA (113%), MDMA (199%), MDEA (207%), MBDB (123%), BDB (72%), PMA (24%), and PMMA (100%). The assay is highly specific and exhibits minimal cross-reactivity with the undesirable, structurally related over-the-counter amphetaminelike drugs. Imprecision results (n = 120) demonstrate an intra-assay < 6.3% CV and an interassay < 9.2% CV as performed by a modified NCCLS protocol. Using the SAMHSA mandatory guidelines of a 500-ng/mL cutoff for the immunoassay and a 250-ng/mL cutoff for GC-MS, the assay detects 164 out of 165 GC-MS-positive samples. For drug abuse testing, the multiplex assay presents an excellent method for the detection of multiple drugs with greater sensitivity and broader detection.