Rox Factor VIII
Rox Factor VIII (800070) is a Chromogenic Kit for the determination of Factor VIII (FVIII) activity in human plasma and FVIII containing concentrates. This kit is for in vitro research use only and should not be used for patient diagnosis or treatment. Manufactured by Rossix AB.
Rox Factor VIII is a chromogenic kit for the determination of Factor VIII (FVIII) activity in human plasma and FVIII containing concentrates. This kit is for in vitro research use only and should not be used for patient diagnosis or treatment. FVIII is a plasma protein of about 230 000 Daltons (230kD), which serves as a cofactor to Factor IXa in its activation of Factor X to Factor Xa. Deficiency of FVIII causes the severe bleeding disorder Hemophilia A. FVIII is stabilized by its binding to von Willebrand Factor (vWF), a multimeric glycoprotein which prolongs the half-life of FVIII in blood circulation. In the presence of Ca2+ and phospholipids, Factor X is activated to Factor Xa by Factor IXa. This reaction is greatly stimulated by FVIII after activation to FVIIIa by thrombin. By using optimal concentrations of Ca2+, phospholipids and an excess of Factor IXa, Factor X and thrombin, the rate of activation of Factor X is directly related to the amount of FVIII in the sample. Factor Xa hydrolyses the chromogenic Factor Xa substrate, Z-D-Arg-Gly-Arg-pNA, thus liberating the chromophoric group pNA. The colour is read photometrically at 405 nm and the generated FXa and thus the intensity of colour is proportional to the FVIII activity in the sample.