The COX (human) Inhibitor Screening Assay Kit directly measures PGF2α by SnCl2 reduction of COX-derived PGH2 produced in the COX reaction. The prostanoid product is quantified via ELISA using a broadly specific antiserum that binds to all the major prostaglandin compounds. This assay includes human recombinant COX-1 and COX-2, allowing the user to screen specific inhibitors. It is an excellent tool for general inhibitor screening or for eliminating false positive leads generated by less specific methods.