A routine assay procedure for monoamine oxidase and its application to human blood platelets

In the radiometric assay procedure for monoamine oxidase separation of the reaction products by ion-exchange column chromatography was optimized. A device was constructed that allowed the separation of 48 samples at the same time. This device can be applied for a great variety of analytical methods. With a 0.1 mM substrate concentration in the incubation mixture, reaction products could be determined with a reproducibility of 2–5%, where the standard deviation depends on the substrate. Using β-phenylethylamine as substrate 20 μg of platelet protein was sufficient for monoamine oxidase activity determinations. The dependence of human blood platelet monoamine oxidase on age and sex were studied using the method.