A new enzymatic method for the demonstration of choline in human seminal stains.

A new, simple method for the identification of seminal stains based on the reaction of choline oxidase with choline is presented. The key reaction is the production of hydrogen peroxide by the oxidase action on choline, whereby hydrogen peroxide reacts with N-ethyl-N-(3-methylphenyl)-N'-acetylethylenediamine and 4-aminoantipyrine (ampyrone) in the presence of peroxidase to produce a purple color so that seminal fluid can be identified. Some data are presented on the sensitivity, stability, and specificity of the present method.