Ordering Recommendation

Not recommended for detecting protein S deficiency; preferred test is Protein S Free, Antigen (0098894). Use to subtype deficiency in known protein S-deficient individuals in combination with Protein S Free, Antigen (0098894), or Protein S, Functional (0030114). Do not order if individual has been on warfarin therapy in the previous 2-4 weeks.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Lt. blue (sodium citrate). Refer to Specimen Handling at aruplab.com for hemostasis/thrombosis specimen handling guidelines.

Specimen Preparation

Transfer 1.5 mL platelet-poor plasma to an ARUP Standard Transport Tube. (Min: 1 mL)

Storage/Transport Temperature

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Serum. EDTA plasma, clotted or hemolyzed specimens.


Ambient: 4 hours; Refrigerated: Unacceptable; Frozen at -20°C: 3 months, at -70°C: 6 months


Microlatex Particle-Mediated Immunoassay




1-2 days

Reference Interval

Age Male Female
1-4 days 12-60% 12-60%
5-29 days 22-78% 22-78%
30-89 days 33-93% 33-93%
90-179 days 54-118% 54-118%
180-364 days 55-119% 55-119%
1-5 years 54-118% 54-118%
6-10 years 41-114% 41-114%
11 years and older 84-134% 63-126%

Interpretive Data

Patients on warfarin may have decreased protein S values. Patients should be off warfarin therapy for two weeks for accurate measurement of protein S.

Compliance Category



Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0030112 Protein S, Total Antigen 27823-4
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Free Protein S Antigen
  • Protein S Antigen, S Protein Antigen
  • Total Protein S Antigen
Protein S, Total Antigen