von Willebrand disease is the most common hereditary bleeding disorder. von Willebrand Factor is necessary for platelet adhesion to injured endothelium. Ristocetin cofactor is useful in assessing binding of von Willebrand Factor to platelet factor GP1b. When combined with other tests, results are useful in categorizing the type of von Willebrand disease.
1.0 mL platelet poor plasma from a Blue Top Tube - 3.2% Na Citrate in a Plastic Vial
6 hours Ambient
30 days Frozen -20°
1 year Frozen -70°
Please submit a separate, frozen vial for each special coagulation assay ordered.
Centrifuge light blue-top tube for 15 minutes at approximately 1500 g within 60 minutes of collection.
Using a plastic pipette, remove plasma, taking care to avoid WBS/platelet buffy layer and place into a plastic vial.
Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10,000/mcL).
Freeze immediately and ship on dry ice.
0.5 mL PP Plasma
50% - 150%
von Willebrand disease is the most common hereditary bleeding disorder. von Willebrand Factor is necessary for platelet adhesion to injured endothelium. Ristocetin cofactor is useful in assessing binding of von Willebrand Factor to platelet factor GP1b. When combined with other tests, results are useful in categorizing the type of von Willebrand disease.
3 to 5 days
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