Factor X (FX), as known as Stuart-Prower factor or prothrombinase, is the first member of the final common pathway (thrombin pathway) in the coagulation cascade. Activated by factor IXa or factor VIIa, Factor X turn into it's activated form,factor Xa (FXa), which is capable of activating factor II (prothrombin) into thrombin.

Our FXa is prepared from bovine plasma, then activated by Russell's viper Venom-factor X activator (RVV-X), and purified by ion exchange chromatography and gel filter chromatography.

FXa is mainly used in anti-FXa activity assay of heparin.