Test Overview
Test Methodology

Latex Immunoassay

Test Usage

Diagnosis of congenital or acquired protein S deficiency states.

Reference Range *

Males: Free 65 - 160%, Total 80 - 160%; Females, age <50 yrs: Free 50 - 160%, Total 70 - 160%; Females, age >=50 yrs: Free 65 - 160%, Total 80 - 160%.

Test Limitations

Lipemic or cloudy specimens may lead to an underestimation of the total Protein S Antigen level. The presence of rheumatoid factor may lead to an overestimation of the total Protein S Antigen level.

Test Details
Days Set Up
Monday - Friday
Analytic Time

2 - 5 days

Soft Order Code
PSTF
MiChart Code
Protein S, Total and Free
Synonyms
  • Protein S Antigen, Free and Total
  • PROTEIN S ANTIGEN, PLASMA
  • PSF
  • PST
  • PROTEIN S ANTIGEN, FREE
  • PROTEIN S ANTIGEN, TOTAL
Laboratory
Sendout
Reference Laboratory
Mayo PSTF (83049)
Section
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in a blue top (citrate 3.2%) tube. Mix by inversion. Specimen should arrive at lab within 3 hours of collection; transport at room temperature. Alternatively, centrifuge, aliquot plasma into a polypropylene plastic vial, and freeze the specimen within 4 hours of collection. Transport frozen specimen on dry ice. Collection of the blood through lines that have been previously flushed with heparin should be avoided. If the blood must be drawn through a VAD (vascular access device), the line should be flushed with 5 mL of saline and the first 5 mL of blood or six dead space volumes of the VAD discarded.

Contraindications
This test is not indicated in patients receiving coumadin therapy.
Blue Top Tube
Normal Volume
1 mL plasma
Minimum Volume
0.5 mL plasma
Additional Information

If the Free Protein S Antigen level is abnormal, Total Protein S Antigen (PST) (MML 80994) will be performed at an additional charge. By ordering this test the clinician acknowledges that additional reflex testing will be performed and billed at a separate additional charge if indicated. Test is sent to Mayo Medical Laboratories.

Billing
CPT Code
85306
Fee Code
22014
Reflex CPT
85305
Reflex Fee Code
20164
LOINC
Z238-6
NY State Approved
No