Arylalkylamine (serotonin) N-acetyltransferase assay using high-performance liquid chromatography with fluorescence or electrochemical detection of N-acetyltryptamine.

A sensitive, rapid, and economical method has been developed for determination of serotonin N-acetyltransferase activity from a variety of enzyme sources. The assay is based upon separation and detection of N-acetyltryptamine formed from tryptamine and acetyl coenzyme A, by means of high-performance liquid chromatography with either electrochemical or fluorometric detection. The limit of sensitivity with both detection methods is less than 20 pmol of N-acetyltryptamine formed per sample. A method for synthesis of N-acetyltryptamine, used as an external standard in the assay, is described.