Prekallikrein Factor, Activity
Use
This test is used to evaluate the cause of an isolated prolonged partial thromboplastin time (PTT) in a patient who is not currently bleeding. It helps in diagnosing prekallikrein (Fletcher factor) deficiency, an uncommon factor deficiency that can lead to abnormal coagulation tests without bleeding symptoms.
Special Instructions
The specimen must be collected in a light blue top tube (sodium citrate). After collection, 2 mL of platelet-poor plasma must be transferred to an ARUP Standard Transport Tube. The sample must be kept critically frozen during storage and transport. Separate samples must be submitted when multiple tests are ordered.
Limitations
The test cannot be performed on serum or EDTA plasma samples. Clotted or hemolyzed specimens are also unacceptable. The stability of the sample is limited to 4 hours at room temperature and 2 weeks when frozen. Samples, once refrigerated, are considered unacceptable for testing.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 52759-8
Result Turnaround Time
1-8 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
2 mL
Minimum Volume
1 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Use a light blue (sodium citrate) top tube for collection. Transfer 2 mL platelet-poor plasma to an ARUP Standard Transport Tube. Ensure the sample remains critically frozen.
Storage Instructions
CRITICAL FROZEN. Separate samples must be submitted when multiple tests are ordered.
Causes for Rejection
Serum, EDTA plasma, clotted or hemolyzed specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |
| Refrigerated | Unacceptable |
| Frozen | 2 weeks |