Factor IX Activity

Profile or Test Panel
Method Clottable
Test Information A one-stage intrinsic system clotting assay is used to measure circulating factor IX levels. Clotting times of dilutions of patient plasma are compared to dilutions of a plasma pool from normal donors, when added to deficient plasma. Levels are reduced by hereditary (Hemophilia B) or acquired factor IX deficiency, factor IX inhibitor, vitamin K deficiency, warfarin therapy, or liver disease.
Additional Test Information Normal ranges are included on testing report and can be made available upon request.
Sample Requirements Whole Blood: 3.2% sodium citrated (blue top) OR
frozen plasma.
Requested Volume Two 5 ml 3.2% sodium citrated (blue top) tubes as whole blood OR
frozen plasma in 4 X 1mL aliquots in plastic tubes
Minimum Volume or Pediatric Volume Frozen Plasma: at least 0.5ml in 2 plastic tubes.
Sample Information Whole blood is preferred for testing, but if it is not possible to send whole blood tubes TO ARRIVE HERE WITHIN 2 HOURS of collection then send frozen plasma. To prepare plasma, centrifuge blue top tubes at 1500g for 15 minutes and remove the plasma and centrifuge a second time at 1500g for an additional 15 minutes. Aliquot approximately 1 ml of plasma into 4 plastic tubes, and freeze.
Shipping Information Whole Blood: Send at ambient temperature (18-25°C) and must be received within the lab in less than or equal to 2 hours after collection.

Frozen Plasma: Send on dry ice

Send samples to:
Bloodworks Northwest
Attn: Hemostasis Laboratory
921 Terry Ave
Seattle, WA 98104

For additional information, please see Ordering Information

Requisition Form RFT- Hemostasis Reference Laboratory
Transaction Code 3210-14
CPT Codes 85250
Test Schedule Monday – Friday
Turn around Time (analytic time) 3 Business Day
Report/Results Fax number required to receive report

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