Chromogenic assays for testing Factor VIII:C activity in plasma or concentrates, in the high or low range.
Factor VIII is a high molecular weight plasma protein which serves as a cofactor to factor IXa in its activation of factor X to factor Xa.
Deficiency of factor VIII causes a severe bleeding disorder, hemophilia A. The severity of this bleeding disorder is inversely related to the factor VIII concentration. Hemophilia A patients are generally classified mild, moderate or severe, according to their factor VIII activity.