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Test Code LAB3550 Von Willebrand Factor Activity

Important Note

For STAT requests, please contact the UW Lab Medicine Resident (LMR) for approval. Call UW Client Support Services (CSS) at (206) 520-4600 and ask for the LMR on call. If approved, notify Seattle Children's lab of approved STAT request.

Additional Codes

VWF SO

Clinical System Name

Von Willebrand Factor Activity

Sample Requirements

Specimen: Whole Blood

Container(s): Lt. Blue/Citrate

Preferred Vol: (1) 2.7 mL

Minimum Vol: (1) 1.8 mL

 

Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volume. Use of a Vascular Access Device for the collection of coag testing is not recommended. Please review the Coagulation Lab Collection Job Aid for detailed instructions. 

Processing Instructions

Deliver whole blood to Coag bench. Coag Technologist will process.

 

Reject due to: clotted, hemolyzed, insufficient quantity (underfill), or improper collection (overfill).

Spin: Y

Aliquot: Y

Temp: -70 C

Storage Location: CPA 2 Freezer ( -70 C) Send Out rack.

 

Specimen should be centrifuged within one hour of collection. Transfer upper 3/4 layer of plasma to plastic tube affixed with large Epic aliquot label. Freeze one aliquot of plasma at -70 C. Preferred plasma volume: 1.0 mL, minimum plasma volume: 0.6 mL. Do not pool. 

Processing Instructions: Offsite & Regional Clinics

Reject due to: clotted, insufficient quantity (underfill), or improper collection (overfill).

Spin: Y

Aliquot: Y

Storage location:  -70 C (preferred) or -20 C. 

 

Specimen should be centrifuged within one hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large sample label. Freeze one aliquot of plasma at -70 C (preferred) or -20 C. Preferred plasma volume: 1.0 mL, minimum plasma volume: 0.6 mL. Do not pool. 

 

Non-Children's Hospital Offsite collection: Ship completely frozen on dry ice.

 

Children's Hospital Regional Clinic collection: Ship completely frozen in frozen Nalgene Labtop cooler with ice pack inside an insulated soft cooler.

Stability

Specimen Type Temperature Time
Plasma Room temp N
  Refrigerated N
  Frozen Y

Performing Laboratory

Harborview Medical Center

Clinical Coagulation Lab

325 9th Ave

Room GWH 47

Seattle, WA 98195

 

Phone Number: (206) 744-3128

Department

Department: Send Outs

 

Phone Number: (206) 987-2563

Send Out Instructions

Reference Test Name: Von Willebrand Factor Activity
Reference Lab Test Code: VWFACT
Instructions: Send out Monday through Friday with the UW courier.

Synonyms

Ristocetin Cofactor Activity; Von Willebrand Factor Activity; VWF Activity

Availability

STAT Performed TAT
N T 7 - 10 d

 

Methodology

Method: Latex Immunoassay (LIA)

Analytical Volume: 1.0 mL Plasma

Limitations:

Reference Range

Units: %

Female Male
Age Range Age Range
0- 50-200 0- 50-200

CPT Codes

85245