A fluorometric assay for total diamines in human urine using human placental diamine oxidase

The detailed procedure for a new fluorometric assay for total diamines in human urine is described. The diamines were purified from the urine by cation-exchange chromatography and incubated with human placental diamine oxidase. Hydrogen peroxide formed in the diamine oxidase reaction was measured fluorometrically by converting homovanillic acid to a highly fluorescent compound in the presence of peroxidase. Because of its simplicity and high sensitivity, our present method seems useful for routine clinical investigation. The data obtained from normal subjects and patients suffering from various forms of cancer are also presented.