Protein S, Total

Panels that include this biomarker

• Protein S Antigen 164517

  2 analytes · Plasma · Fasting not stated · Turnaround 2 - 3 days

  Method and collection

  Method

  Total and free PS antigens are measured by latex immunoassay.

  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.

  Collection

  Citrated plasma samples should be collected by double centrifugation. 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 (i.e., "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 for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap, and recentrifuge for 10 minutes. Use a second plastic pipette to remove the plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.

  Reference notes

  Protein S Antigen6-8 Age | Range 0 to 6 m | 12–60% >6 m | 60–140% Total: In newborns, total PS levels are lower than in adults (12% to 60%). Levels gradually reach adult ranges by six months of age.6

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• Protein S Antigen:Factor VII Antigen Ratio 164530

  2 analytes · Plasma · Fasting not stated · Turnaround 5 - 7 days

  Method and collection

  Method

  See individual tests.

  Preparation

  Do not draw from an arm with a heparin lock or heparinized catheter.

  Collection

  Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.4 Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio.5,6 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 unless the sample is collected using a winged (butterfly) collection system. With a winged blood collection set, a discard tube should be drawn first to account for the dead space of the tubing and prevent under-filling of the evacuated tube.7,8 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 alternative 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. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.

  Reference notes

  Protein S , Total Age | Range 0 to 6 m | 12–60% >6 m | 60–140% Factor VII Antigen 59–178% Protein S/Factor VII Antigen Ratio 0.5–2.2

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• Protein S Deficiency Profile 117754

  3 analytes · Plasma · Fasting not stated · Turnaround 2 - 3 days

  Method and collection

  Method

  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.

  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.

  Collection

  Citrated plasma samples should be collected by double centrifugation. 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 for 10 minutes and carefully remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells. Deliver to a plastic transport tube, cap, and recentrifuge for 10 minutes. Use a second plastic pipette to remove the plasma, staying clear of the platelets at the bottom of the tube. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. Please print and use the Volume Guide for Coagulation Testing to ensure proper draw volume.

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Single-analyte tests

• Protein S Antigen, Total 5165

  Plasma · Fasting not stated · Turnaround Report available: 3 days

  Method and collection

  Method

  Immunoturbidimetric

  Collection

  Draw blood in a light blue-top tube containing 3.2% sodium citrate, mix gently by inverting 3-4 times. Centrifuge 15 minutes at 1500 g within one hour of collection. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial(s). Plasma must be free of platelets (<10,000/uL). Freeze immediately and transport on dry ice.

  Reference notes

  70-140 % normal

  Quest Diagnostics catalog page

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Panels that include this biomarker

• Protein S Antigen, Total and Free 36457

  2 analytes · Plasma · Fasting not stated

  Method and collection

  Method

  Immunoturbidimetric

  Collection

  Draw blood in blue-top tube containing 3.2% sodium citrate, mix gently by inverting 5-10 times. Centrifuge 15 minutes at 2500-3500 RPM. Using a plastic pipette, remove plasma, taking care to avoid the WBC/platelet buffy layer and place into a plastic vial. Centrifuge a second time and transfer platelet-poor plasma into a new plastic vial. Plasma must be free of platelets (<10, 000/µL). Freeze immediately and ship on dry ice.

  Quest Diagnostics catalog page

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