• Resolving discrepancies when results of complementary laboratory tests (eg, F8A / Coagulation Factor VIII Activity Assay, Plasma; VWACT / von Willebrand Factor Activity, Plasma; and VWAG / von Willebrand Factor Antigen, Plasma) are abnormally low or discordant
• Subtyping von Willebrand disease (VWD) (primarily identify variants of type 2 VWD)
• Aiding in determining appropriate treatment
• Identifying variants of type 2 VWD that have fewer of the largest multimers, have unusually large multimers, or have qualitatively abnormal "bands" that indicate an abnormal von Willebrand factor structure

•  Fasting: 8 hours, preferred but not required

• Specimen should be collected prior to coagulation factor replacement therapy

Two (2) Lt blue Sodium citrate (NaCit) - 2.7mL

• Do not draw from an arm with a heparin lock or heparinized catheter.
• Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.
• The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples.
• When non-citrate tubes are collected for other tests, collect sterile and non-additive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube.
• Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes
• Immediatley following collection, mix sample thoroughly by gentle inverting 8 - 10 times, to prevent clotting

1. Process Platelet Poor Plasma (P.P.P) 
   • Coag – how to prepare a specimen for special coagulation testing
2. Transfer plasma to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as Na cit plasma
3. Freeze immediately

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Frozen (strict) - 42 days

Gross hemolysis, lipemia or icterus

Agarose Gel Electrophoresis/Infrared Dye-Labeled Antibody Detection

An interpretive report will be included