Cayman’s 15-hydroxy Prostaglandin Dehydrogenase (15-PGDH) Substrate Screening Assay Kit provides a robust and EAsy-to-use platform for identifying novel substrates of the metabolic enzyme 15-PGDH. Measurement of 15-PGDH activity is carried out by monitoring the rate of NAD+ reduction to NADH. The reduction of NAD+ to NADH is accompanied by an increase in fluorescence at 445 nm following excitation at 340 nm. Prostaglandin E2 (PGE2) is included as a positive control while 15-keto PGE2, an inactive metabolite of PGE2 formed by 15-PGDH, is included as a negative (background) control. This assay is also able to detect “slow” substrates, which are utilized by 15-PGDH less efficiently than PGE2.