Determination of 5'-nucleotidase activity in human erythrocytes and plasma using high-performance liquid chromatography.

A method is described for the determination of 5'-nucleotidase activity in human erythrocytes and plasma. Using reversed-phase high-performance liquid chromatography; the product (uridine) was separated from the substrate (uridine-5'-monophosphate) in less than 4 min. The activity determined closely agreed with that determined by the conventional method, in which the inorganic phosphate released is measured. The present method eliminates the need for dialysis of enzyme solution prior to the assay, and offers several advantages over other assay methods, including high sensitivity.