Test Code F11 Factor XI (F11) Assay
Collection Container
Light Blue
Specimen Required
Platelet poor plasma, whole blood if received in laboratory within 4 hours of collection
Special Handling Instructions
Spin down, remove plasma and spin again. Double centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
Specimen Volume
Platelet poor plasma: 1 mL aliquot, Whole blood: 2.7 mL
Minimum Specimen Volume
Platelet poor plasma: 0.5 mL, Whole blood: 2.7 mL.
Transport Temperature
Platelet poor plasma: frozen, Whole blood: ambient temperature
Specimen Stability
Whole blood: 4 hours
Reasons for Rejection
Hemolyzed, clotted, Whole blood >4 hours old
Methodology
Activated Partial Thromboplastin Clot-Based Assay
Days and Times Performed
7 am - 3 pm, Monday - Friday
Turnaround Time
1 - 3 days, depending on receipt in laboratory
Reference Ranges
50-200%
CPT Code
85270
LOINC Code
3226-8
EMR Interface Order Code
33200
Critical Values
≤ 25%