Determination of aspartate aminotransferase activity by high-performance liquid chromatography

A sensitive and reproducible assay of aspartate aminotransferase activity based on UV detection of the reaction products after their separation by HPLC is described. The main advantage is the direct measurement of the enzyme activity as micromoles of product (glutamate) formed within a known period of time without any coupled reaction. Further, with the chromatographic method, all components of the reaction mixture are identified, allowing the reaction course to be controlled and the possible presence of side-reactions to be monitored.