Protein S, Free
Use
Confirmation and characterization of protein S (PS) congenital deficiency
Special Instructions
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Refer to Coagulation Collection Procedures for directions. Avoid warfarin (Coumadin®) therapy for two weeks and heparin therapy for two days prior to the test. Do not draw from an arm with a heparin lock or heparinized catheter.
Limitations
Gross hemolysis, clotted specimens, or frozen specimens that thaw in transit may be rejected. Specimens that are improperly labeled will also be rejected. Incorrect anticoagulant volume can lead to inaccurate results. Testing schedules may vary and additional time may be required for confirmatory tests.
Methodology
Immunoassay (Latex Immunoassay (LI))
Biomarkers
LOINC Codes
- 27821-8
- 27821-8
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio. The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. If using a butterfly collection system, a discard tube should be drawn first.
Patient Preparation
Avoid warfarin (Coumadin®) therapy for two weeks and heparin therapy for two days prior to the test. Do not draw from an arm with a heparin lock or heparinized catheter.
Storage Instructions
Freeze.
Causes for Rejection
Gross hemolysis; clotted specimen; frozen specimen thawed in transit; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 28 days |
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