Factor XIa Activity Assay Kit (Colorimetric)

Factor XI or plasma thromboplastin antecedent (EC 3.4.21.27), the zymogen form of factor XIa, is a serine protease. In humans, Factor XI is encoded by the F11 gene. Factor XI (FXI) circulates as a homo-dimer in its inactive form activated into factor XIa by factor XIIa (FXIIa) via the "contact pathway", thrombin, and self-activation by its active form (FXIa). The deficiency of factor XI causes the rare hemophilia C which is an autosomal recessive disorder characterized by lower spontaneous bleeding, but excessive blood loss during surgical procedures. Low levels of factor XI also occur in many other disease states, including Noonan syndrome. High levels of factor XI have been implicated in thrombosis. Factor XIa also activates factor IX which, in turn, activates factor X in the coagulation cascade. BioVision's Factor XIa activity assay kit utilizes the ability of factor XIa to cleave a synthetic substrate to release p-Nitroaniline (pNA) which can be quantitatively measured by a colorimetric assay (OD 405 nm). The kit is easy-to-use and can detect Factor XIa (as low as 1 mPEU) from plasma and purified protein samples.