Factor IX Activity, Clotting

Last Modified: 9/22/2021 2:45:20 PM

Medical Necessity Documentation:  
Client Notes:  
Patient Preparation:  
Specimen Requirements:

1.0 mL platelet poor plasma from a Blue Top Tube - 3.2% Na Citrate in a Plastic Vial

Collection Instructions: Centrifuge light blue-top tube for 15 minutes at approximately 1500 x g within 60 minutes of collection. Using a plastic pipette, remove plasma, taking care to avoid WBCs/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (< 10,000/uL). Freeze immediately and ship on dry ice.
Minimum Volume: 0.5 mL Platelet Poor Plasma
Transport & Storage: Temperature/Stability: Unacceptable Ambient
Unacceptable Refigerated
14 days Frozen
Rejection Criteria: Received room temperature • Received refrigerated • Received thawed • Hemolysis
Reference Range: 60 -160% of normal
Critical Ranges:  
Test Comments:  
Methodology: Photometric Clot Detection
Clinical Significance: This test is useful to evaluate a prolonged aPTT. The second most common form of hemophilia is caused by deficiency of factor IX. Hemophilia B is an x-linked disorder affecting between 1 in 25,000 to 30,000 males.
Documentation: Limitations: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: Decrease; Heparin (UFH or LMWH): no effect to inhibitor pattern; Dabigatran or Argatroban (Thrombin Inhibitors): no effect to inhibitor pattern; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect to inhibitor pattern.
Custom Panel: No


Turn Around Time: 5 to 7 days
Days Performed: Tuesday, Thursday, Saturday
Sites Performed: Quest - Chantilly
PHL Test Code: FACT9
EPIC Test Code: LAB308
Send Out Test Code: 352X
Alternate Test Names: Christmas Factor; Factor IX Activity; Factor IX Assay; Hemophilia B
Included Tests:  
CPT Coding: 85250

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