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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%