Von Willebrand Factor Normal Reference Plasma is lyophilised plasma standardised using World Health Organisation reference material to give consistent 90-110% of von Willebrand factor activity.

Intended Use
Normal Reference Plasma is used as the source of von Willebrand factor in the preparation of a standard activity curve in a von Willebrand factor assay. 

Principle
Von Willebrand factor (vW factor, VIIR, WF, Ristocetin Cofactor) is the property of the factor VII protein which is responsible for the agglutination of platelets in the presence of Ristocetin.  Decreased quantities or abnormalities of the von Willebrand factor are associated with the von Willebrand Syndrome, thus making quantitation of the factor most valuable in the diagnosis and avaluation of this coagulopathy.  Levels of von Willebrand factor are determined by the ability of a test plasma and Ristocetin to induce agglutination of a standardized platelet suspension.