Factor IX Activity and Human Inhibitor

Test Code

CPT Codes
85250, 85335

Preferred Specimen
2 mL (x2) frozen platelet-poor plasma collected in two 3.2% sodium citrate (light blue-top) tube

Minimum Volume
1 mL (x2)

Platelet poor plasma: 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 the WBC/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/mcL). Freeze immediately and ship on dry ice. Do not thaw.

Transport Container
Plastic screw-cap vial (x2)

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 14 days

Clot Based Assay • Photometric Clot Detection

Setup Schedule
Set up: Tues; Report available: 3-10 days

Reference Range
Factor IX Activity 60-160 % normal
Factor IX Inhibitor ≤0.4 BU

Clinical Significance
Factor IX Human Inhibitor provides a quantitative determination of inhibitors. This aids in developing treatment strategies for patients with hemophilia.

Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.