A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #

Von Willebrand Cofactor Activity

Test Code
VWCOF


Alias/See Also

Epic: LAB307




Preferred Specimen

Specimen Type: Platelet-poor plasma
Collection Container: Light blue top (citrate)
Specimen Volume: 1 mL




Minimum Volume
0.5 mL


Instructions
  1. Draw blood into a light blue (sodium citrate) tube.  Be sure to fill tubes completely.
  2. Mix gently 5 to 6 times (do not over mix).
  3. Centrifuge the sample for 10 minutes.
  4. Using a pipette, aliquot plasma into a plastic vial being careful not disturb the buffy coat.
  5. Centrifuge the plasma sample a second time for 10 minutes
  6. Using a pipette, aliquot the top portion of plasma into a plastic vial.  Be careful not to disturb the sediment at the bottom (leave approx. 0.25 mL of plasma at the bottom).
  7. Label each tube as "Plasma."
  8. Immediately freeze samples
 
For complete instructions, see Platelet Poor Plasma Instructions.


Transport Container

Plastic vial




Specimen Stability

Plasma
Room temperature: 4 hours
Refrigerated: Unacceptable
Frozen: 1 month




Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Unacceptable Specimens: Samples that are short draws, clotted or have excessive hemolysis, icterus or lipemia should not be used, as they may yield incorrect results.


Performing Laboratory

Inova Laboratories

2832 Juniper Street

Fairfax, VA 22031




Last Updated: March 30, 2023
Last Review: N. Wolford, March 30, 2023


The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.