VWF ACT

Von Willebrand Factor Activity, Plasma

EPIC Test Procedure Code: LAB2470

Performing Lab:
Referral Laboratory
Container Type:
Light blue top (sodium citrate) tube
Specimen Type:

Platelet Poor Plasma

Preferred Volume:
2 mL
Minimum Volume:
1 mL
Collection Procedure:
Specimen Processing:

1. Centrifuge specimen in a centrifuge that has been validated to ensure platelet poor plasma.
2. Immediately transfer the plasma to a stoppered, plastic tube and centrifuge again for 10 minutes. 
3. Transfer the supernatant plasma into a screw-capped, plastic vial and send frozen at ≤ -20°C, if possible.
4. If unable to centrifuge, forward unprocessed sodium citrate whole blood (minimum volume: 2 mL) to the laboratory promptly at room temperature only.

Store and Transport:
Frozen (plasma)
Stability:

 The unspun specimen must arrive within 2 hours of collection.

Frozen - 28 days (Freeze/thaw cycles: stable x3)

Unacceptable Condition:

Gross hemolysis; clotted specimen; frozen specimen thawed in transit; improper labeling

CPT Codes:

85245 - VWF Activity (EAP 30023010)

Method:
In this ristocetin cofactor assay, the patient plasma is mixed with formalin-fixed platelets in the presence of ristocetin.12 The extent of platelet agglutination detected photo-optically is proportional to the vWF activity of the sample
Notes:

Note: VWF AG “von Willebrand Factor Antigen, Plasma” and
FVIII “Coagulation Factor VIII (8) Assay, Plasma” are recommended in
conjunction with VWF ACT “von Willebrand Factor Activity, Plasma.”

Lab Personnel

Please login to see billing, ordering, and reporting instructions.