Laboratory Services

Coagulation Factor IX Activity Assay, Plasma

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Updated Test Information:

Test Description
Coagulation Factor IX Activity Assay, Plasma
Synonym(s)

Factor 9, UOW1152

Test ID
F9
General Information

Clinical assay interference and limitations: Patients on bivalirudin (Angiomax), dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa) and argatroban (Novastan) may show prolonged clotting times. This may cause an under-estimation of the factor concentrations. Emicizumab (Hemlibra) will affect all PTT-based assays and will overestimate the factor concentration. Certain recombinant F9 formulation may give unreliable results with this assay. A chromogenic F9 assay is available at Bloodworks Northwest for these patients.


Outside clients should fill and submit Coagulation Patient Clinical History Form.

Container Type

3 or 5 mL Blue Top (Citrate) Tube

Specimen Type

Blood

Specimen Requirements

Entire Specimen

Specimen Collection / Processing Instructions

The Laboratory MUST process specimen, within 4 hrs of blood collection.


Centrifuge for 10 minutes, remove plasma & re-spin plasma for another 10 minutes. Decant & Freeze plasma (minimum 1.0 mL) @ -20°C to -80°C. Send frozen on dry ice.

Department (code)

Coagulation (COAG)

Methodology

Stago STA Clottable Factor assays

Estimated TAT

Report by end of next business day

Testing Schedule

Monday - Friday

CPT Code(s)

85250

Reference Range File View/Download File
STAT Orderable (Y/N)

Yes

Performing Lab

UW

LOINC Code(s)