Evaluation of the ADx REA assay for determination of ethanol in serum and urine.

The Abbott ADx REA assay (ADx) for the determination of ethanol in human serum and urine was evaluated. The within-run precision of a urine sample containing 3.00 g/L ethanol resulted in a coefficient of variance (CV) of 2.1% (n = 20). The within-run precision of a serum sample containing 1.47 g/L ethanol resulted in a CV of 2.3% (n = 20). The between-run precision of the TDx REA ethanol assay controls yielded 0.50 +/- 0.02 g/L ethanol (target value, 0.50 g/L) with a CV of 3.0% (n = 6); 1.03 +/- 0.03 g/L ethanol (target value, 1.00 g/L) with a CV of 2.7% (n = 6); and 2.56 +/- 0.07 g/L ethanol (target value, 2.50 g/L) with a CV of 2.8% (n = 6). Results of an intermethod comparison study of clinical serum and urine ethanol determinations by gas chromatography (x) and ADx (y) yielded by regression analysis y = 0.993x - 0.04 g/L (r = 0.985; n = 92) for serums and y = 0.974x - 0.02 g/L, (r = 0.991; n = 75) for urines. No significant interference was seen with low molecular weight alcohols or ketones.