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HelpTest 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.