Test ID F_9 Coagulation Factor IX Activity Assay, Plasma
Useful For
Diagnosing deficiencies, particularly hemophilia B (Christmas disease)
Assessing the impact of liver disease on hemostasis
Investigation of a prolonged activated partial thromboplastin time
Special Instructions
Method Name
Optical Clot-Based
Reporting Name
Coag Factor IX Assay, PSpecimen Type
Plasma Na CitOrdering Guidance
Coagulation testing is highly complex, often requiring the performance of multiple assays and correlation with clinical information. For that reason, consider ordering a Coagulation Consultation.
Necessary Information
If priority specimen, mark request form, give reason, and request a call-back.
Specimen Required
Specimen Type: Platelet-poor plasma
Patient Preparation: Patient must not be receiving Coumadin (warfarin) or heparin therapy.
Collection Container/Tube: Light-blue top (3.2% sodium citrate)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Specimen must be collected prior to factor replacement therapy.
2. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.
3. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
4. Aliquot plasma into a plastic vial, leaving 0.25 mL in the bottom of centrifuged vial.
5. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or ideally, at or below -40° C.
Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma Na Cit | Frozen | 14 days |
Reference Values
≤6 months: Normal, full-term newborn infants or healthy premature infants may have decreased levels (≥20%), which may not reach adult levels for 180 or more days postnatal.* (Literature derived)
>6 months: 65-140%
*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing.
Day(s) Performed
Monday through Saturday
Performing Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
85250
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
F_9 | Coag Factor IX Assay, P | 3187-2 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
F_9 | Coag Factor IX Assay, P | 3187-2 |
Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.Disease States
- Hemophilia B
Report Available
1 to 3 daysNY State Approved
YesTesting Algorithm
For information see Hemophilia Testing Algorithm
Forms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.