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Test Code FACTOR 11 Factor 11 Assay

Important Note

Method is affected by hemolysis and by improper specimen collection/processing. Patients on hirudin (Refludan) and argatroban (Novastan) may show prolonged clotting times due to the direct thrombin inhibition. This may cause an under-estimation of the factor concentrations.

Clinical System Name

Factor 11 Assay

Synonyms

Factor 11 Activity
Factor XI Activity

Sample Requirements

Specimen: Whole Blood

Container(s): Lt. Blue/Citrate

Preferred Vol: (3) 1.8 mL or (1) 2.7 mL

Minimum Vol: (2) 1.8 mL

 

Note: For stat requests outside the M - F 0800-1500 window, contact the Lab Medicine resident for approval.

Processing Instructions

Reject due to:

Spin: N

Aliquot: N

Temp: RT

Storage location:  Core 6 Freezer ( -70 C) Send Out rack.

 

Note: Deliver blood to Core Coag bench. Coag Technologist will process. Specimen should be centrifuged within 1hour of collection. Spin whole blood, remove plasma. Transfer upper 3/4 layer of plasma to plastic tube and make 2 aliquots 0.6 mL, affix large label and store in -70 freezer, Send Out rack.

 Available STAT M - F 8 am - 3 pm. For other times contact the Lab Medicine resident for approval. Please notify the Special Coag lab on Friday (206-744-2621) if sending a stat factor XI on the weekend.

 

Off-site collection:   Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volumel. Use of a Vascular Access Device for the collection of coag testing is not recommended. If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the Lt Blue/Citrate tube by use of the blood transfer device.

Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze 2 aliquots of 0.6 mL plasma in plastic tubes at -70C.

Ship frozen on dry ice.

 Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volumel. Use of a Vascular Access Device for the collection of coag testing is not recommended. If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the Lt Blue/Citrate tube by use of the blood transfer device.

Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze 2 aliquots of 0.6 mL plasma in plastic tubes at -70C.

Ship frozen on dry ice.

Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volumel. Use of a Vascular Access Device for the collection of coag testing is not recommended. If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the Lt Blue/Citrate tube by use of the blood transfer device.

Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze 2 aliquots of 0.6 mL plasma in plastic tubes at -70C.

Ship frozen on dry ice.

Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volumel. Use of a Vascular Access Device for the collection of coag testing is not recommended. If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the Lt Blue/Citrate tube by use of the blood transfer device.

Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze 2 aliquots of 0.6 mL plasma in plastic tubes at -70C.

Ship frozen on dry ice.

  

      

 Preferred method of collection is venipuncture with vacuum fill. Test results are affected by incorrect blood volumel. Use of a Vascular Access Device for the collection of coag testing is not recommended. If this method is used it requires a 5 cc clearing volume; 3 cc for size 2 French catheter or smaller. Blood must be trasferred to the Lt Blue/Citrate tube by use of the blood transfer device.

Specimen should be centrifuged within 1 hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large computer label. Freeze 2 aliquots of 0.6 mL plasma in plastic tubes at -70C.

Ship frozen on dry ice.

Stability

Specimen Type Temperature Time
  Room temp  
  Refrigerated  
  Frozen  

 

Availability

STAT Performed TAT
Yes, M - F 8 am - 3 pm. Drawn daily, Performed M - F at HMC Coag Lab 1 - 3 d

 

Performing Laboratory

University of Washington

Dept. of Laboratory Medicine

Harborview Medical Center Coag Lab

1959 NE Pacific St, NW220
Seattle, WA 98195

 

Phone Number: (206) 520-4600

Department

Department:  Send Outs

 

Phone Number: (206) 987-2563

 

Reference Range

0 - 1 month 23 - 150%
1 - 3 months 27 - 150%
3 - 6 months 41 - 150%
6m - 1 year 38 - 150%
> 1 year 50 - 150%

 

Methodology

Method: Stago STA Clottable Factor assay

Analytical Volume: 1.0 mL citrate plasma

Limitations:

CPT Codes

85270

 

Send Out Instructions

Reference Test Name: Factor XI (11) Activity Assay
Reference Test Number: F11
Instructions: Send routines M - F with the UW courier.