PROTEIN S ACTIVITY, PLASMA

Test Code
LAB3041212


Preferred Specimen
One 3 mL blue top tube

Pediatric: One 1.8mL pediatric blue top tube


Minimum Volume
Required for Testing: 1 mL plasma


Instructions
Tube must be filled to the etched line. Immediately after drawing gently invert the specimen 3 to 4 times. Do not shake.



Samples must be centrifuged at 3000 rpm for 10 minutes or using a high-speed centrifuge.  Platelet poor plasma should be separated into 1 ml aliquots.  Samples should be frozen within one hour (best practice), however samples stable for 4 hours.  Samples must remain frozen during transport. Any samples that are received thawed are not suitable for testing.


Transport Temperature
Frozen ( two 1 mL plasma aliquots)


Specimen Stability
Ambient: 4 hours if cap has not been removed or punctured

Frozen: 6 months (-70C)


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Clotted specimen, improperly filled tube, gross hemolysis, TURBID SAMPLES.


Methodology
PT Clot-based assay on ACL-TOP
 


Setup Schedule
Tuesday and Thursday


Clinical Significance
Patients should be off oral anticoagulation therapy (Coumadin) for two weeks to accurately measure protein S levels.


Performing Laboratory
West Virginia University Hospital, Inc.



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.