Small molecule inhibitors of sEH may hold promise as therapeutics for the treatment of hypertension and vascular inflammation. Cayman’s fluorescence-based sEH Inhibitor Screening Assay provides a convenient method for screening epoxide hydrolase inhibitors. The assay utilizes (3-phenyl-oxiranyl)-acetic acid cyano-(6-methoxy-naphthalen-2-yl)-methyl ester (PHOME) as a substrate. Hydrolysis of PHOME by epoxide hydrolase produces the highly fluorescent 6-methoxy-2-naphthaldehyde which can be analyzed using an excitation wavelength of 330 nm and emission wavelength of 465 nm. Each kit contains buffer, substrate, and sufficient human recombinant sEH for 100 tests.