A comparison of a microdiffusion method for ethanol and the Abbott TDx ethanol assay

A simple, rapid ethanol screen based on a microdiffusion technique (Analytical Systems, Marion Laboratories) has been evaluated and compared to an established enzymatic procedure (Abbott TDx). They showed agreement in 484 of 488 biological specimens and all control specimens. They disagreed on 4 specimens--3 positive by the Marion method and negative by TDx, and 1 positive by TDx and negative by Marion. The discrepancies could not be elucidated because insufficient quantities of samples remained. The microdiffusion method was found to be a dependable, reproducible screening test for the presence of reducing volatiles in urine. There is insufficient data to evaluate its effectiveness in serum or whole blood. It is particularly suited for screening negative specimens before quantitating positive specimens by a suitable alternate quantitative method.