Thrombin enzyme (Factor IIa, EC 184.108.40.206), a Serine protease, is an important clotting factor in the coagulation cascade that involves the conversion of soluble fibrinogen to insoluble active fibrin strands. In this pathway, Prothrombin is proteolytically converted into an active Thrombin. Thrombin is also a potent vasoconstrictor and mitogen implicated as a major factor in vasospasm following subarachnoid hemorrhage. Ruptured cerebral aneurysm blood clots around a cerebral artery releases thrombin, which in turn induces acute and prolonged narrowing of the blood vessel, potentially resulting in cerebral ischemia and infarction (stroke). In addition, it is a pro-inflammatory enzyme that may influence the onset and progression of atherosclerosis. Biovision's Thrombin activity assay kit utilizes the ability of Thrombin to proteolytically cleave a synthetic substrate and release a fluorophore, AMC, which can be easily quantified by fluorescence reader. This assay kit is simple, rapid and can detect Thrombin activity as low as 1 ng in samples.