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Test Code VWFAC VON WILLEBRAND FACTOR ACTIVITY, PLASMA

Additional Codes

Software Test Code
Label Text                                    

VWFAC                                  

EPIC LAB9355

Performing Laboratory

NorDx Laboratories

Useful For

Diagnosing von Willebrand’s disease when used in conjunction with “Factor VIII Assay”, “Von Willebrand Factor Antigen”, and “Platelet Aggregation With Ristocetin” assay

Method Name

(LIA) Immunoturbidmetric assay

Reference Values

50-150 %

Days and Times Test Performed

Monday or Friday, sometimes varies

Report Available

Up to 7 days

Specimen Type

Plasma

Preferred Container

Light Blue Top Tube (Sodium Citrate) – Tube must be full at time of collection.

Specimen Collection and Handling

Collect specimen as follows:

1. Draw blood in light blue-top (3.2% sodium citrate) tube(s). Tube(s) must be full upon collection.

2. Separate plasma from cells as soon as possible within 4 hours of collection in a centrifuge at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes.

3. Using a plastic transfer pipette (do not use a glass pipette) decant the plasma to a screw-capped, plastic (polypropylene) vial. Glass vials will not be accepted.

4. Spin the plasma again at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes. Note: Double spinning the specimen ensures platelet poor plasma (<10,000 uL)

5. Divide the plasma into as many 0.5-1.0 mL aliquots as possible and cap the vial(s) tightly.

6. Place tubes upright and flash freeze specimen(s) immediately at ≤ – 20° C or below.

7. Send specimen(s) FROZEN on dry ice.

Click here to view the Procedure for Collecting a Specimen from an A-line

Specimen Stability Information

Specimen Type: Plasma

Room Temp: 4 Hours

Note: Whole blood that remains capped and unspun is stable for up to 4 hours when stored at room temperature (18 – 24°C). Frozen plasma is stable 2 weeks @ -20°C and 12 months @ -70°C. Blue top tubes for coag assays must not be refrigerated or placed on ice.

Add On Capable

Yes

Advance Beneficiary Notice Requirements

No ABN Required

CPT Code Information

CPT Code

CPT Description

CPT Disclaimer

85245 Clotting, Factor VIII von Willebrand (VW) Factor, Ristocetin Cofactor  

Performing Laboratory Location

NorDx Laboratories

LOINC Code Information

6014-5

Keywords

VON WILLEBRAND FACTOR

Rejection Information

Underfilled (< 90%), clotted, high hematocrit (> 55%), or grossly hemolyzed