Yale New Haven Hospital

Department of Laboratory Medicine
Test Directory

[ Test Name Index ]

[ Home & References ]

Factor XI assay

Lab Section: 

Coagulation

 

Lab Location: 

Main Lab

Test ID: 

LAB309

 

Synonyms:

FXI

 

Methodology: 

Clotting

Schedule: 

Mon-Fri

Reported: 

3 - 5 days

Specimen Requirements: 

Collection: 2.7 mL Blood in a Blue Top Tube.
Pediatric volume: 2.7 mL.
Tubes must be full.
Transport: Whole blood may be transported at ambient or refrigerated temperature. Separated plasma, not yet frozen, may be transported at refrigerated temperature, while frozen plasma should be sent on dry ice to prevent thawing in transit.
Unacceptable conditions: QNS; Overfilled; Clotted

 

Notes: 

Reflex Criteria: FXI assay auto reflex to PTT. Abnormal results reflex to an MD interpretation.

Clinical Indications: Unexplained prolongation of PTT in the investigation of bleeding tendency; familial history of Factor XI deficiency.

Three (3) clotting factor assays may be performed from one full 2.7-mL tube. If additional clotting factor assays are needed, additional tubes are necessary.

Reference Interval: 

Age Limit

Sex

Normal Range

Units

0 - 1 Days

Any

10.0-65.0

%

2 Days - 5 Days

Any

25.0-85.0

%

6 Days - 1 Months

Any

25.0-80.0

%

1 Months - 3 Months

Any

40.0-95.0

%

4 Months - 999 Years

Any

50.0-150.0

%

 

CPT Code(s): 

85270

Last Changed: 

8/16/2017 1:22 PM

Last Reviewed: 

8/16/2017 1:22 PM