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Test Code VWAG von Willebrand Antigen

Specimen Type

Plasma

Container/Tube

Light blue top tube, 3.2% sodium citrate

Offsite Collection Instructions

Whole blood sample must arrive in the laboratory within
three hours of specimen collection.

 

If transport time exceeds three hours, follow centrifugation
instructions:

  • Samples must be centrifuged at >2500 x g for 10 minutes
    at room temperature.
  • Carefully remove the plasma from the cells using a plastic
    transfer pipette avoiding the buffy coat.
  • Aliquot removed plasma into 2 plastic tubes containing a
    minimum of 500 uL of specimen in each tube.
  • The plasma samples must then be frozen at -20 C.
  • Once solidly frozen, they must be shipped on dry ice.
    Samples that have thawed in transit will be rejected.

Note: For clients who do not have access to dry ice DO
NOT freeze the specimen. Follow the centrifugation instructions and
send fresh plasma or send whole blood sample. It now becomes
vital that the specimen arrives in the lab within three hours of
collection.

Turnaround Time

8 hours

Test Includes

vWF, Antigenic Level

Preferred Volume

1 mL

UCMC Collection Instructions

Specimens may be collected and sent to the laboratory at any
time.

Test can be added on to an existing order up to 4 hours
following the time of blood draw.

Additional Information

All 3.2% sodium citrate light blue top tubes require a ratio
of 9 parts blood to 1 part anticoagulant (example: a 3.0 mL tube
requires 2.7 mL blood added to 0.3 mL of anticoagulant).

Fee Code

30585246

Synonyms

vW Ag, VWFAG, VWAG

Test Usage

Used to measure vWF antigen level

STAT Turnaround Time

n/a

Specimen Minimum Volume

0.5 mL

DAY(S) AND TIME(S) PERFORMED

Test performed 7 days a week from 8:00 am to 10:30 pm.
Samples received in the lab after 10:30 pm will be run the next
morning.

STAT DAY(S) AND TIME(S) PERFORMED

Not Available

CPT

85246

Method Name

Latex Immunoassay

Reference Values

55-200%

Reject Due To

Specimens that have wrong ratio of blood to anticoagulant
(fill volume), clotted or grossly hemolyzed.