Ordering Recommendation

Not recommended for detecting protein C deficiency; preferred test is Protein C, Functional (0030113). Use to subtype deficiency in known protein C-deficient individuals. Do not order if individual has been on warfarin therapy in the previous 2-4 weeks.

Mnemonic
PROT C
Methodology

Enzyme Immunoassay

Performed

Sun-Sat

Reported

1-2 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

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

Specimen Preparation

Transfer 2 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.

Remarks
Stability

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

Reference Interval

1-4 days: 17-53%
5-29 days: 20-64%
30-89 days: 21-65%
90-179 days: 28-80%
180-364 days: 37-81%
1-5 years: 40-92%
6-10 years: 45-93%
11 years and older: 63-153%

Interpretive Data

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

Compliance Category

FDA

Note
Hotline History
N/A
CPT Codes

85302

Components
Component Test Code* Component Chart Name LOINC
0030111 Protein C, Total Antigen 27820-0
* 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.
Aliases
  • Protein C Antigen, Plasma
  • Protein C Immunologic
Protein C, Total Antigen