Location out of bounds
Back to Test Catalog

Protein S Activity

Order Code: 1041

Sample Requirements

Citrated Plasma (light blue top)

Additional Sample Requirements

Protein S activity is measured by a prothrombin-time-based clotting method. Patients should be off warfarin for at least 4 weeks before drawing a sample. The assay kit manufacturer has demonstrated the assay to be unaffected by levels of unfractionated heparin or low molecular weight heparin up to 2 IU/mL, but the results may be artifactually elevated in samples containing dabigatran or rivaroxaban. Platelet contamination of plasma samples causes an under-recovery of Protein S level, and proper sample preparation is required. Age and gender specific reference intervals are used.

Shipping Information


Requested Volume

0.5 ml

Minimum/Pediatric Volume

0.3 ml

CPT Codes




Turnaround Time

7 days


This website uses cookies to ensure you get the best experience on our website. Learn more