Test Details
Methodology
See individual tests.
Result Turnaround Time
3 - 7 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
Factor XI activity; factor XII activity; high molecular weight kininogen (Fitzgerald factor); prekallikrein (Fletcher factor)
Footnotes
Specimen Requirements
Specimen
Plasma, frozen
Volume
4 mL (2 mL in each of two tubes)
Container
Blue-top (sodium citrate) tube
Collection Instructions
Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.1 Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio.2,3 The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples, except when using a winged blood collection device (ie, "butterfly"), in which case a discard tube should be used.4,5 When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternate anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. Centrifuge and carefully remove the plasma using a plastic transfer pipette, being careful not to disturb the cells. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.
Storage Instructions
Freeze.
Patient Preparation
Do not draw from an arm with a heparin lock or heparinized catheter.
Causes for Rejection
Severe hemolysis; improper labeling; clotted specimen; specimen diluted with IV fluids; samples thawed in transit; improper sample type; sample out of stability.
LOINC® Map
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
500436 | Contact Factor Evaluation | 500674 | Factor XI Activity | % | 3226-8 | |
500436 | Contact Factor Evaluation | 500367 | Factor XII Activity | % | 3232-6 | |
500436 | Contact Factor Evaluation | 500195 | Prekallikrein Assay | % | 52759-8 | |
500436 | Contact Factor Evaluation | 500461 | Kininogen Activity | % | 52754-9 | |
Order Code | 500436 | |||||
Order Code Name | Contact Factor Evaluation | |||||
Order Loinc | ||||||
Result Code | 500674 | |||||
Result Code Name | Factor XI Activity | |||||
UofM | % | |||||
Result LOINC | 3226-8 | |||||
Order Code | 500436 | |||||
Order Code Name | Contact Factor Evaluation | |||||
Order Loinc | ||||||
Result Code | 500367 | |||||
Result Code Name | Factor XII Activity | |||||
UofM | % | |||||
Result LOINC | 3232-6 | |||||
Order Code | 500436 | |||||
Order Code Name | Contact Factor Evaluation | |||||
Order Loinc | ||||||
Result Code | 500195 | |||||
Result Code Name | Prekallikrein Assay | |||||
UofM | % | |||||
Result LOINC | 52759-8 | |||||
Order Code | 500436 | |||||
Order Code Name | Contact Factor Evaluation | |||||
Order Loinc | ||||||
Result Code | 500461 | |||||
Result Code Name | Kininogen Activity | |||||
UofM | % | |||||
Result LOINC | 52754-9 |