This assay uses the patient's plasma to agglutinate platelets in the presence of ristocetin. The von Willebrand activity is quantitated by comparing the rate of agglutination against a normal reference curve. Separate plasma or serum from cells and aliquot in appropriately labeled plastic tubes. Ship frozen samples on dry ice via overnight delivery. This disorder is characterized by a qualitative and or quantitative deficiency of the von Willebrand factor.
Patient plasma is exposed to normal platelets and ristocetin.
The von Willebrand activity is quantified by comparing the rate of agglutination against a normal reference curve. Biohazard Bag in Styrofoam shipping box. Centrifuge ASAP after collection until platelet count is less than labeled with patient name, SS number, Date. Freeze at -20 C. Ship frozen samples on dry ice via overnight delivery. Separate plasma from cells and aliquot in appropriately labeled plastic tubes.