Pathology Handbook

Assay name

Ristocetin Cofactor

von Willebrand factor Antigen

Alternative names

RiCoF, von Willebrand activity, vWF activity

vWF antigen

Request Group

VWR

VWA

Registration Instructions

Use VWA is vWF antigen (single test) only is requested. If von Willebrand studies or von Willebrand factor activity are requested, use VWR, F8.

Collection & Request Instructions

Usually ordered as part of von Willebrand factor (vWF) studies, which include von Willebrand factor antigen (vWF Ag), FVIII and Ristocetin (RicoF).

If no other tests in vWF studies are ordered, contact request doctor to confirm that no other tests are required.

Usually ordered as part of von Willebrand factor (vWF) studies, which include von Willebrand factor antigen (vWF Ag), FVIII, vWF collagen binding assay (CBA) and Ristocetin (RicoF).

If no other tests in vWF studies are ordered, contact request doctor to confirm that no other tests are required.

Processing Instructions

Centrifuge immediately for 15 minutes at 2000-2500 g.

Then aliquot plasma into a separate tube. Centrifuge again for 15 minuts at 2000-2500 g.

Centrifuge immediately.