7 days
Total PS and free PS antigen: Total PS and free PS antigens are measured by latex immunoassay (IA). PS activity: The patient plasma is added to PS-depleted normal plasma with normal levels of all factors but PS. The mixture is supplemented with excess aPC, and factor V is then added. The extent of prolongation of the time to clot formation after calcium chloride is added is proportional to plasma PS activity.
Accredited Laboratory Partner
Contact Technical Support
Includes protein S antigen and activity. Used in hypercoagulability workup.
Plasma
1 mL
Blue top (sodium citrate) tube
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.
Citrated Plasma samples should be collected by double centrifugation
| Temperature | Period |
|---|---|
| Frozen | 28 days |
| Freeze/thaw cycles | Stable x3 |
7 days
Total PS and free PS antigen: Total PS and free PS antigens are measured by latex immunoassay (IA). PS activity: The patient plasma is added to PS-depleted normal plasma with normal levels of all factors but PS. The mixture is supplemented with excess aPC, and factor V is then added. The extent of prolongation of the time to clot formation after calcium chloride is added is proportional to plasma PS activity.
Accredited Laboratory Partner
Contact Technical Support
Includes protein S antigen and activity. Used in hypercoagulability workup.
Plasma
1 mL
Blue top (sodium citrate) tube
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.
Citrated Plasma samples should be collected by double centrifugation
| Temperature | Period |
|---|---|
| Frozen | 28 days |
| Freeze/thaw cycles | Stable x3 |