Ristocetin Cofactor is the in vitro activity of the von Willebrand
factor which is responsible for the agglutination of platelets in
the presence of Ristocetin.
Patient plasma is added to Formalin Fixed Platelets in the presence
of Ristocetin and agglutination is measured over a time period.
Decreased levels of Ristocetin Cofactor Activity are associated with
von Willebrand Disease.
