Protein S Activity and Antigen, Total [7039X]

Test Code

CPT Codes
85305, 85306

Protein S Antigen, Protein S Activity

Preferred Specimen
1 mL (x2) plasma collected in 3.2% sodium citrate (light blue-top) tubes

Minimum Volume
0.5 mL (x2)

Please submit a separate, frozen vial for each special coagulation assay ordered. Please submit two frozen vials of plasma and ship frozen samples on dry ice to laboratory.

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/mcL). Freeze immediately and transport on dry ice.

General Drawing Instructions: Refer to Quest Diagnostics Nichols Institute Directory of Services under Specimen Collection section, Coagulation Testing, for further information on specimen processing.

Transport Container
Plastic screw-cap vial

Transport Temperature

Specimen Stability
Room temperature: Unacceptable
Refrigerated: Unacceptable
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

See individual tests

Setup Schedule
Set up: Tues-Sat; Report available: Next day

Protein S, Activity: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: decrease; Heparin (UFH or LMWH): may falsely increase at values approximately greater than 1.0 IU/mL; Dabigatran or Argatroban (Thrombin Inhibitors): may falsely increase; Rivaroxaban or Apixaban (Factor Xa Inhibitors): may falsely increase.
Protein S Antigen, Total: Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: no effect to decrease; Heparin (UFH or LMWH): no effect; Dabigatran or Argatroban (Thrombin Inhibitors): no effect; Rivaroxaban or Apixaban (Factor Xa Inhibitors): no effect.

Reference Range
Protein S Antigen 70-140 % normal
Protein S Activity  
   Male 70-150 % normal
   Female 60-140 % normal

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.