von Willebrand Factor Activity (Ristocetin Cofactor)
:0030250
Mnemonic: RCF
Ordering Recommendation:
Order in conjunction with von Willebrand Factor Antigen (0030285) and Factor VIII Activity (0030095) as part of initial workup of suspected von Willebrand disease.
Methodology:
Platelet Agglutination
Performed:
Mon-Sat
Reported:
1-3 days
Specimen Required:
Collect: Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.
Specimen Preparation: Transfer 1.5 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)
Storage/Transport Temperature:CRITICAL FROZEN.Separate specimens must be submitted when multiple tests are ordered.
Unacceptable Conditions: Serum. Hemolyzed or non-frozen specimens.
Stability (collection to initiation of testing): Ambient: 4 hours; Refrigerated: Unacceptable; Frozen: at -20°C: 3 months; Frozen at -70°C: 6 months
