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Factor VIII Activity

Alias:

Coagulation Factor VIII Activity Assay, Plasma, Factor VIII, Factor 8

Methodology:

Note: STAT testing is available from MercyOne in Des Moines. The physician should be contacted to verify that the testing cannot wait to be performed the next day at Pathology Laboratory.

Performed:

Monday through Friday. Samples must be at Pathology Laboratory by 9:00am.

Analytical Time:

8 hours

Testing Laboratory:

Pathology Laboratory

Laboratory Section:

Core Laboratory

Factor VIII Activity

Container/Tube Type:

Light Blue (Citrate)

Collection Information:

Collect blood in a blue top tube. Tube must be filled to a 1:9 ratio- see tube label for proper amount of blood

Transport Information:

Platelet Poor Plasma
Centrifuge Specimen
Recommended centrifuge speed is 1500 x G for at least 15 minutes. Be careful that the tubes are evenly balanced when placing them into the centrifuge. When the centrifuge stops, carefully remove and rack tubes. Be aware that an unbalanced centrifugation, speed too slow, or centrifugation for too short of a spin time may all lead to an increase number of cells in the plasma which could contribute to a clotted specimen or erroneous results.
Remove Plasma
To remove plasma, start from the top, gently draw specimen into pipette as you go further down tube. Leaving approximately 0.5mL of plasma will insure that you do not disturb the buffy coat and cell layer.
Second Spin
Plasma separated from cells goes back into the centrifuge for a second spin. Balance and centrifuge the tubes. Failure to perform a second spin will result in plasma containing too many platelets which interfere with some coagulation testing and is a contributing factor for a clotted specimen.
Transfer Plasma to Aliquot Tubes
Pipette plasma from second spin tube into labeled aliquot tubes without disturbing the bottom 0.5mL.
Specimen Storage
Promptly freeze specimens after processing.

Minimum Sample Volume: Minimum amount of analytical sample (serum, plasma, urine, CSF, etc.) required to perform an assay once. Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory or reflex testing. In some situations, a minimum specimen volume may result in a QNS (Quantity Not Sufficient) result, requiring a second specimen to be collected.

Minimum amount of analytical sample (serum, plasma, urine, CSF, etc.) required to perform an assay once. Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory or reflex testing. In some situations, a minimum specimen volume may result in a QNS (Quantity Not Sufficient) result, requiring a second specimen to be collected.

0.25 mL of frozen plasma for testing. Must collect a full tube, if difficult collection request a 1.7 mL "pediatric blue top" from the laboratory.

Remarks:

3.2% buffered sodium citrate is the only acceptable anticoagulant concentration for this testing. Tube should be inverted several times immediately after collection, mixing blood and anticoagulant, to prevent clotting. Tube must be filled with appropriate volume to obtain the proper 9:1 ratio blood to anticoagulant-see tube label.

Unacceptable Conditions:

Clotted, Hemolyzed or Does not meet collection, storage or transport requirements

Stability

Frozen Stability:

14 days

Factor VIII Activity

Sunquest Order Code:

FVIII

Epic Number: The test code used to identify this assay in Epic

LAB306

CPT Code:

85240

Factor VIII Activity

Modified:

3/8/2013 10:56:51 AM