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Test ID S_FX Protein S Activity, Plasma

Useful For

Second-order testing for diagnosis of congenital or acquired protein S deficiency for example, as an adjunct to initial testing based on results of protein S antigen assay (free protein S antigen, with or without total protein S antigen assay)

 

Evaluating patients with a history of venous thromboembolism

Method Name

Optical Clot-Based

Reporting Name

Protein S Activity, P

Specimen Type

Plasma Na Cit


Specimen Required


See Coagulation Guidelines for Specimen Handling and Processing in Special Instructions.

 

Patient Preparation: Patient must not be receiving Coumadin.

Specimen Type: Platelet-poor plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.

2. Aliquot plasma into a plastic vial leaving 0.25 mL in the bottom of centrifuged vial.

3. Freeze specimen immediately (no longer than 4 hours after collection) at ≤-40° C, if possible.

Additional Information:

1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

2. Each coagulation assay requested should have its own vial.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Na Cit Frozen 14 days

Reference Values

Males: 65-160%

Females

<50 years: 50-160%

≥50 years: 65-160%

Newborn infants have normal or near-normal free protein S antigen (≥50%), although total protein S antigen is usually below the adult reference range. There are insufficient data concerning protein S activity in normal neonates, infants, and children; but normal or near-normal activity (≥50%) probably is present by age 3 to 6 months.

Day(s) Performed

Monday through Friday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

85306

LOINC Code Information

Test ID Test Order Name Order LOINC Value
S_FX Protein S Activity, P 27822-6

 

Result ID Test Result Name Result LOINC Value
S_FX Protein S Activity, P 27822-6

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

Report Available

1 to 4 days

NY State Approved

Yes