Sign in →

Test Code PST Protein S Antigen, Total, Plasma


Specimen Required


Only orderable as part of a profile. For more information see PSTF / Protein S Antigen, Plasma.

 

Specimen Type: Platelet-poor plasma

Patient Preparation: Patient must not be receiving heparin or Coumadin. If the patient is being treated with Coumadin, this should be noted. Coumadin will lower protein S.

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

Submission Container/Tube: Plastic vials

Specimen Volume: 1 mL in 2 plastic vials each containing 0.5 mL

Collection Instructions:

1. For complete instructions, see Coagulation Guidelines for Specimen Handling and Processing.

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

3. Aliquot plasma into separate plastic vial leaving 0.25 mL in the bottom of centrifuged vial.

4. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or ideally, at -40 degrees C or below.

5. Send specimens in the same shipping container.

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.


Useful For

Aiding in the investigation of patients with a history of thrombosis

Method Name

Only orderable as part of a profile. For more information see PSTF / Protein S Antigen, Plasma.

 

Latex Immunoassay

Reporting Name

Protein S Ag, Total, P

Specimen Type

Plasma Na Cit

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Na Cit Frozen 14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Reference Values

Only orderable as part of a profile. For more information see PSTF / Protein S Antigen, Plasma.

 

Males: 80-160%

Females:

<50 years: 70-160%

≥50 years: 80-160%

Normal, full-term newborn infants or healthy premature infants may have decreased levels of total protein S (15%-50%), but because of low levels of C4bBP, free protein S may be normal or near the normal adult level (≥50%). Total protein S reaches adult levels by 90-180 days postnatal.*

 

*See Pediatric Hemostasis References section in Coagulation Guidelines for Specimen Handling and Processing

Method Description

This assay is performed using the Diagnostica Stago LIATEST-Protein S kit on the Instrumentation Laboratory ACL TOP using automated latex immunoassay methodology. The kit methodology is comprised of a reagent with microlatex particles coated with specific antihuman-protein S antibodies. Patient plasma containing protein S antigen is combined with the latex reagent causing the antibody-coated latex particles to agglutinate and form aggregates. The aggregates form diameters greater than the wavelength of the light (405 nm) passing through causing absorption of the light. This change in absorption is measured over time and reported as delta optical density. The increase in absorption is proportional to the concentration of total protein S antigen present in the patient plasma.(Package insert: Liatest Protein S. Diagnostica Stago; 11/2015)

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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.

CPT Code Information

85305

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PST Protein S Ag, Total, P 27823-4

 

Result ID Test Result Name Result LOINC Value
PST Protein S Ag, Total, P 27823-4