ARUP's Laboratory Test Directory

Factor XI, Activity : 0030110

Mnemonic: F11

Ordering Recommendation: Order to diagnose factor XI deficiency (hemophilia C).
Methodology: Clotting
Performed: Mon-Fri
Reported: 1-4 days
Specimen Required: Collect: Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation: Transfer 2 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)

Storage/Transport Temperature: CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Remarks:

Unacceptable Conditions: Serum. Non-frozen or hemolyzed specimens.

Stability (collection to initiation of testing): Ambient: 4 hours; Refrigerated: 4 hours; Frozen: 2 weeks
Reference Interval:
1-4 days: 10-66%
5-29 days: 23-87%
30-89 days: 27-79%
90-179 days: 41-97%
180-364 days: 38-134%
1-5 years: 56-150%
6 years:  52-120%
7-9 years: 70-138%
10-11 years: 66-137%
12-13 years: 68-138%
14-15 years:  57-129%
16-17 years: 65-159%
18 years and older: 56-153%
CPT Code(s): 85270
Cross References: Antihemophilic Factor C (Factor XI, Activity), Coagulation Factor XI Activity Assay, Plasma (Factor XI, Activity), Intrinsic Factor Proteins (Factor XI, Activity), Intrinsic Factors (Factor XI, Activity), Plasma Thromboplastin Antecedent (PTA) (Factor XI, Activity)