Von Willebrand Antigen VWF AG

Synonyms

Allscripts (AEHR) Order Name

von Willebrand Factor Antigen

Sunrise Clinical Manager (SCM) Order Name

von Willebrand Factor Antigen

EPIC Order Name

von Willebrand Factor (vWF) Antigen

Clinical Info

Specimen Type

Blood

Container

Blue Top Tube

Collection Instructions

Container/Tube:  Light blue-top (3.2% sodium citrate) tube
Specimen: 1.0 ml citrated plasma
Transport Temperature:  Frozen Plasma
Collection Instructions:                                        
If the light blue top tube is the only tube to be drawn and will be collected using a butterfly set, a “discard” tube (either a plain[non-additive] or light blue) must be partially drawn just to completely fill the collection tubing with blood before collecting the light blue top for testing.  Failure to perform this step will result in an under-filled tube that the laboratory will reject. Allow blood to fill the tube completely to the line on the tube.  The ratio of blood to anticoagulant is critical in coagulation testing and at least a 90% fill is required. Immediately mix the specimen by gently inverting the tube 4-6 times to completely mix with the anticoagulant.  Failure to perform this can result in a clotted sample, which is unacceptable for testing. If centrifugation is possible, spin down, remove the plasma to a clean plastic transport tube using a plastic transfer pipette, and spin the plasma again.  Remove the plasma with a clean plastic transfer pipette to a fresh transport container and freeze this citrated platelet-poor plasma immediately.  A double centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.   Each coagulation assay requested should have its own vial of citrated plasma, 1.0mL each.
If centriguation is not available, arrange for a STAT pick up.

Transport Instructions

Frozen Plasma

Specimen Stability

8 hours at 20 C
24 hours at 2-8 C
1 month at -20 C
6 months at -40 to -80 C

Methodology

Microlatex Turbidimetry-ACL-Top/IL

Days Performed

Two to three times per week

Performing Laboratory

Northwell Health Laboratories

CPT

85246

PDM

5601080

Result Interpretation

63%-170%

Forms