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Laboratory Test Directory

Von Willebrand Workup


Name Method Department Units
Von Willebrand Workup Clot detection
Platelet aggregation
Core Lab, Coagulation

Battery Members

PT;APTT;Platelet Function Analysis;Ristocetin Cofactor;Quant. Factor VIII:C;Von Willebrand Antigen;Fibrinogen;Thrombin Time

Specimen Requirements

Platelet poor plasma

Container Type Container Size Specimen Volume

Blue plastic tube (Citrate)

2.7 mL 15 mL

Frozen - 2 week(s)

Specimen Preparation

  • Fill tubes to appropriate mark.
  • Mix by gentle inversion immediately after collection
  • Centrifuge, remove plasma/serum and freeze
  • Plasma must be platelet free

Reasons for Rejection

  • Over or under filled tube
  • Clotted specimen
  • Not received within specified time frame
  • Refrigerated specimen
  • Gross hemolysis
  • Wrong collection tube
  • Capillary specimen
  • Specimen collected in glass tube


Frozen plasma is UNACCEPTABLE for Platelet Function Analysis. Whole blood in sodium citrate, kept at room temperature, MUST be submitted within 3.5 hours of collection if Platelet Function Analysis will be performed. Platelet Function Analysis must arrive in the lab by 2200 (see Platelet Function Analysis test for more information). *Note: If the Platelet Function Analysis is not desired as part of the workup, please refer to test "von Willebrand Workup without Platelet Function Analysis" (LIS test code: VWS). Sample testing is batched (several tests are not performed daily). Reflexive testing is the Factor VIII Multimer Analysis (LIS test code: XVWFM) ordered by the pathologist. A pathologist's interpretation (billed through Pediatric Pathology associates (PPAC)) may be ordered and charged. A Pathologist's consult/interpretation may extend the expected turnaround time. Five 2.7 mL collection tubes should be drawn from the patient to perform all tests in the workup. For frozen plasma: Centrifuge citrate tubes according to Lab policy, remove platelet-poor plasma and freeze.

CPT Code

  • 85245
  • 85240
  • 85576 (x2)
  • 85384
  • 85730
  • 85610
  • 85670
  • 85246