Protein S Activity with Reflex to Protein S Antigen, Total and Free
Use
Measurement of plasma free Protein S antigen is the initial screen for Protein S deficiency. A decreased free Protein S antigen prompts reflex testing for total Protein S antigen to help distinguish hereditary versus acquired deficiency states as part of a thrombophilia evaluation.
Special Instructions
Not provided.
Limitations
Not provided.
Methodology
Immunoassay (Latex Immunoassay)
Biomarkers
LOINC Codes
- Z238-6
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL plasma (0.5 mL per tube × 2)
Minimum Volume
0.5 mL plasma (0.25 mL per tube × 2)
Container
blue top (citrate 3.2%) tube; polypropylene plastic vial if frozen
Collection Instructions
Mix by inversion. Specimen arrive within 3 hours at room temp; or centrifuge, aliquot plasma and freeze within 4 hours; transport frozen on dry ice. Avoid heparin line draws.
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