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Test Code FACTOR 12 Factor 12 Assay

Important Note

Method is affected by hemolysis and improper specimen handling. Patients on Direct Thrombin Inhibitors (Novastan, argatroban, bivalirudin) 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 12 Assay

Synonyms

Factor 12 Activity
Factor XII Activity

Sample Requirements

Specimen: Whole Blood

Container(s): Lt. Blue/Citrate

Preferred Vol: (1) 2.7 mL

Minimum Vol: (1) 1.8 mL

 

Note: Preferred method of collection is venipuncture with vacuum fill.  Test results are affected by incorrect blood volume.  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 a  blood transfer device to ensure proper fill. 

Specimen should be processed within one hour of collection.

Processing Instructions

Deliver blood to Core Coag bench. Coag Technologist will process.

 

Reject due to: Clotted, hemolyzed, insufficient quantity, or improper collection.

Spin: Y

Aliquot: Y

Temp: -70 C

Storage Location: CPA 2 Freezer ( -70 C) Send Out rack.

 

Specimen should be centrifuged within one hour of collection. Transfer upper 3/4 layer of plasma to plastic tube affixed with large Epic aliquot label. Freeze one aliquot of plasma at -70 C. Preferred plasma volume: 1.0 mL, minimum plasma volume: 0.6 mL. Do not pool. 

 

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 one hour of collection. Transfer upper 3/4 layer of plasma to plastic tube affixed with large Epic aliquot label. Freeze one aliquot of plasma at -70 C. Preferred plasma volume: 1.0 mL, minimum plasma volume: 0.6 mL. Do not pool. 

Stability

Specimen Type Temperature Time
Citrated platelet-poor plasma Room temp N
  Refrigerated N
  Frozen Y

 

Availability

STAT Performed TAT
N 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

CPT Codes

85280

 

Methodology

Method: Stago STA Clottable Factor assay

Analytical Volume: 1.0 mL citrate plasma

Limitations:

Reference Range

Age % Activity
< 1 month 11 - 150
1 - 3 months 17 - 150
3 - 6 months 25 - 150
6 months - 1 year 39 - 150
> 1 year 30 - 150

 

Send Out Instructions

Reference Test Name: Factor XII Activity
Reference Test Number: F12
Instructions: Send out M - F with the UW courier.