[Use of the ADH/REA method (Abbott Tdx-REA) in forensic blood alcohol determination]

The ethanol determination using the ADH/REA method (Abbott TDx-REA) is based on the principle of radiative energy attenuation (REA) applying the classic ADH-method. However, instead of measuring the extinction of the reaction product NADH, a chromogen formed by a coupled diaphorase reaction is measured. Serum, whole blood and urine are used for ethanol determination without prior treatment. The following analytical procedures such as sampling, addition of reagents and measuring are automated. Sample solutions of 100 to 200 microliters should be used. Daily calibration of the apparatus is recommended. Both precision and reproducibility meet the requirements of BAC-assays in forensic specimens. The results obtained by using gas chromatography and ADH/REA method show an excellent correlation (factor r = 0.9977). The ADH/REA method has proved to be a reliable assay procedure in routine determination of the BAC in forensic samples.