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Test Code 4775 von Willebrand Factor Multimer (vWF Multimer)

Performing Laboratory

BloodCenter of Wisconsin



Specimen Requirements

Call Laboratory Medicine resident at digital pager 314-747-1320 for approval before drawing the specimen (with the exception of St. Louis Children’s Hospital patients).


Specimen must arrive within 4 hours of draw.


Specimen Type: Plasma

Container/Tube: Light-blue top (citrate)

Specimen Volume: 2 Full tubes

Specimen Minimum Volume: 0.5 mL

Collection Instructions:

1. Draw a discard tube prior to light-blue top (citrate) tube.
2. Tube should remain stoppered. Allow tube to fill by vacuum completely. Mix by gentle inversion.
3. Blood should not be drawn through an indwelling catheter or an A-V shunt.

4. Clotted blood or an insufficient specimen is not acceptable.

5. Avoid hemolysis.

Additional Information: If possible, include result of von Willebrand factor antigen with specimen.

Day(s) Test Set Up


Turnaround Time:
STAT: not available
Routine: 7 to 10 days after receipt at reference laboratory

Reference Values

An interpretive report will be provided.

Test Classification and CPT Coding


Additional Information

For BJH Laboratory Use Only

Analyte Stability:

4 hours at ambient temperature, unprocessed

Laboratory Processing Instructions:

BJH Chemistry will forward to the performing laboratory. With the exception of SLCH patients, Laboratory Medicine approval at 314-747-1320 is required prior to forwarding specimen. Centrifuge specimen for 15 minutes. Transfer top two thirds of plasma (minimum volume:  0.5 mL) into a labeled, plastic, screw-cap vial, and freeze. Send specimen frozen in dry ice to the BloodCenter of Wisconsin. Ship Monday through Thursday only.

Specimen Transport Temperature

Ambient/Refrigerate NO/Frozen NO