von Willebrand Factor (vWF) Screen

Specimen:

Test Code

VWP

Specimen Name

von Willebrand Factor (vWF) Screen

Collect

3 - Blue Top (Na Citrate)

Submit

4 - 0.5 mL (Min: 2 - 0.5 mL) plasma aliquots

Special Handling

If multiple specimens are collected, adhere to policy for order of draw. Tubes MUST be full. DO NOT overfill or underfill. Tube MUST be mixed immediately after filling with blood. Gently mix tube by inverting 5 to 6 times. If testing cannot be completed within 4 hours, prepare platelet poor plasma and freeze at -20 C.

Rejection Criteria

Specimens collected in an anticoagulant other than 3.2% sodium citrate. Under or overfilled specimens. Clotted specimens. Grossly hemolyzed, lipemic, or icteric specimens. Refrigerated or frozen whole blood specimens.

Stability

Room temperature: 4 hours. Frozen -20 C: 1 month. If specimen cannot be tested within 4 hours, prepare platelet poor citrated plasma and freeze plasma in 0.5 mL aliquots, CRITICAL FROZEN.

Methodology

Instrumentation Laboratory ACL Top 750

Performed

Monday- Friday

Reported

1-4 days

CPT Codes

  • 85240
  • 85244
  • 85245

Components

Additional Information

The presence of Rheumatoid Factor over 50 IU/mL may produce an overestimation of VW antigen results. DO NOT PUT ALL PLASMA IN ONE ALIQUOT TUBE.

Disclaimer:

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Updated test information can only be guaranteed by using this website.

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Test Information

How to Label Your Sample

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Common Test Phrases

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Common Lab Definitions

  • Serum 
  • Plasma 
  • STT