| Ordering Code | 715 |
|---|---|
| Test Name | Protein S Activity |
| Alias | Functional Protein S |
| Preferred Specimen | Plasma |
| Preferred Container | Citrate, 3.2% (Lt Blue) |
| Other Specimen/Container | Whole Blood in Citrate, 3.2% (Lt Blue) if testing is done within 4 hours. |
| Optimum Volume | Plasma: 1 mL Whole Blood: Entire tube |
| Collection Instructions | Draw full tube Mix tube well Patient should be off of coumadin for 2 weeks and off high levels of heparin for 48 hours before sample collection Consult pathology for further information. |
| Handling Instructions | Double centrifuge to produce platelet-poor plasma, avoid the WBC/platelet buffy layer, separate and freeze at -20 deg C immediately. Do NOT thaw once specimen is frozen. |
| Transport Requirements | Preferred method of transport is frozen plasma. |
| Specimen Stability | Ambient: 4 Hours Whole Blood Ambient: 4 Hours Plasma (Aliquoted) Frozen: 1 Month Plasma |
| Rejection Criteria | Clotted, Contaminated, Hemolyzed, Improperly filled or underfilled tube, Collected in the wrong anticoagulant, Mislabeled, Specimen older than stability limits |
| Avail. Stat | NO |
| Analytic Time | Up to 1 Week |
| Methodology | Clot Detection |
Reference range(s)
The reference ranges listed below are valid on this date of June 29, 2025.
| Component | Age | Male Norm | Male Critical Low | Male Critical High | Female Norm | Female Critical High | Female Critical Low | Units | Add'l info |
|---|---|---|---|---|---|---|---|---|---|
| Protein S Activity | ALL | 63.5-149.0 | 63.5-149.0 | % |