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HelpTest Code FACTOR 12 Factor 12 Assay
Clinical System Name
Factor 12 Assay
Sample Requirements
Specimen: Whole Blood
Container(s): Lt. Blue/Citrate
Preferred Vol: (1) 2.7 mL
Minimum Vol: (1) 1.8 mL
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. Please review the Coagulation Lab Collection Job Aid for detailed instructions.
Processing Instructions: Main Campus
Deliver whole blood to Coag bench. Coag Technologist will process.
Reject due to: clotted, hemolyzed, insufficient quantity (underfill), or improper collection (overfill).
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.
Processing Instructions: Offsite and Regional Clinics
Reject due to: clotted, insufficient quantity (underfill), or improper collection (overfill).
Spin: Y
Aliquot: Y
Storage location: -70 C (preferred) or -20 C.
Specimen should be centrifuged within one hour of collection. Double spin, transfer upper 3/4 layer of plasma to plastic tube affixed with large sample label. Freeze one aliquot of plasma at -70 C (preferred) or -20 C. Preferred plasma volume: 1.0 mL, minimum plasma volume: 0.6 mL. Do not pool.
Non-Children's Hospital Offsite collection: Ship completely frozen on dry ice.
Children's Hospital Regional Clinic collection: Ship completely frozen in frozen Nalgene Labtop cooler with ice pack inside an insulated soft cooler.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Citrated platelet-poor plasma | Room temp | N |
| Refrigerated | N | |
| Frozen | Y |
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
Synonyms
Factor 12 Activity
Factor XII Activity
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | Drawn daily, Performed M - F at HMC Coag lab | 1 - 3 d |
Methodology
Method: Electromagnetic mechanical clot detection assay by STA-R MAX
Analytical Volume: 400 uL plasma
Limitations: Method is affected by hemolysis, insufficient quantity (underfill), improper collection (overfill), improper processing, and improper storage. High hematocrit greater than or equal to 56% requires a citrate adjusted tube.
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.
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 |
CPT Codes
85280
Send Out Instructions
| Reference Test Name: | Factor XII Activity |
| Reference Test Number: | F12 |
| Instructions: | Send out M - F with the UW courier. |