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22448 Factor Assay-12 (XII)

Factor Assay-12 (XII)
Test Code: F-XII
Synonyms/Keywords
​Factor XII Activity
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ 0.75 mL​ 0.75 mL​ 0.5 mL​
Collection Processing Instructions
​One 0.75 mL citrated Blue Top Tube (BTT) plasma aliquot.
If more than one coagulation test is ordered, a separate aliquot is needed for each test.
-Collect in Citrated Blue Top Tube (BTT)
-Citrate anticoagulant must be adjusted for HCT >55%
-Tube must be at least 90% full
-Invert completely 3-4 times (without shaking) to mix
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
​Plasma ​Frozen ​6 months
Rejection Criteria
Clotted or Hemolyzed
​Contamination with IV or Hickman Line fluids
​Specimens that thaw during storage or transport
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield ​Monday through Friday ​Less than 2 hours Modified APTT/optical clot detection/Siemens BCSXP​
Reference Range Information
Performing Location Reference Range
​Marshfield 60-140%​
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85280
Synonyms/Keywords
​Factor XII Activity
Ordering Applications
Ordering Application Description
​Centricity ​Factor-XII
​Cerner ​Factor XII Assay
​COM ​Factor Assay-12 (XII)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ 0.75 mL​ 0.75 mL​ 0.5 mL​
Collection Processing
​One 0.75 mL citrated Blue Top Tube (BTT) plasma aliquot.
If more than one coagulation test is ordered, a separate aliquot is needed for each test.
-Collect in Citrated Blue Top Tube (BTT)
-Citrate anticoagulant must be adjusted for HCT >55%
-Tube must be at least 90% full
-Invert completely 3-4 times (without shaking) to mix
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
​Plasma ​Frozen ​6 months
Rejection Criteria
Clotted or Hemolyzed
​Contamination with IV or Hickman Line fluids
​Specimens that thaw during storage or transport
Reference Range Information
Performing Location Reference Range
​Marshfield 60-140%​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield ​Monday through Friday ​Less than 2 hours Modified APTT/optical clot detection/Siemens BCSXP​
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85280
For most current information refer to the Marshfield Laboratory online reference manual.