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.
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.