A direct, rapid, radioassay for adenosine diphosphatase

Abstract Radiolabelled adenosine diphosphate [β 32 P 1 ]ADP was synthesized from radioactive orthophosphate and adenosine-5′-monophosphate with dicyclohexylcarbodiimide. The purified radioactive adenosine diphosphate was used as the substrate in a rapid, direct, one-step assay for adenosine diphosphatase in human neutrophilic leukocyte homogenates. Certain kinetic properties of the enzyme activity have been determined.