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Test Code FVIII FACTOR VIII (8) ASSAY

Important Note

This test is NOT for patients who have received Hemlibra in the last 28 days.

 

For those patients, please order a Mayo miscellaneous test for CHF8.

Specimen Requirements

  1. Draw blood in light blue-top (3.2% sodium citrate) tube(s). Tube(s) must be full upon collection.
  2. Separate plasma from cells as soon as possible within 4 hours of collection in a centrifuge at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes.
  3. Using a plastic transfer pipette (do not use a glass pipette) decant the plasma to a screw-capped, plastic (polypropylene) vial. Glass vials will not be accepted.
  4. Spin the plasma again at 2,500 rpm for 15 minutes or 3,000 rpm for 10 minutes. Note: Double spinning the specimen ensures platelet poor plasma (<10,000 uL)
  5. Divide the plasma into as many 0.5-1.0 mL aliquots as possible and cap the vial(s) tightly.
  6. Place tubes upright and flash freeze specimen(s) immediately at ≤ – 20° C or below.
  7. Send specimen(s) FROZEN on dry ice.

Click here to view the Procedure for Collecting a Specimen from an A-line

 

Specimens will be rejected if under filled (<90%), clotted, high hematocrit (>55%), or grossly hemolyzed.

 

Reference Values

FACTOR VIII

Adults: 50-200%

 

Specimen Stability Information

Room Temp: 4 Hours

 

Note: Whole blood that remains capped and unspun is stable for up to 4 hours when stored at room temperature (18 – 24°C). Frozen plasma is stable 2 weeks @ -20°C and 12 months @ -70°C. Blue top tubes for factor assays must not be refrigerated or placed on ice.

 

Add On Capable

Yes – if testing is added before the specimen is past 4 hour stability limit at room temperature. Add on testing also possible if plasma is still available frozen @ -70°C. Please contact the Bramhall Special Coagulation Laboratory to verify that frozen plasma is still available to perform the request.

 

Days and Times Test Performed

Monday through Friday, 8:00 am-3:00 pm

 

Report Available

Approximately 48 hours for STAT collections

Approximately 1 week for routine collections

 

CPT Code

85240 Clotting, Factor VIII (AHG), 1-stage