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22981 Protein C Activity (Functional)

Protein C Activity (Functional)
Test Code: PROT-CF
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ 0.75 mL ​ 0.75 mL​ 0.5 mL ​
Collection Processing Instructions
​One 0.75 mL citrated Blue Top Tube (BTT) plasma aliquot.
If more than one coagulation test is ordered, a separate aliquot is needed for each test.
-Collect in Citrated Blue Top Tube (BTT)
-Citrate anticoagulant must be adjusted for HCT >55%
-Tube must be at least 90% full
-Invert completely 3-4 times (without shaking) to mix
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
​Plasma ​Frozen ​6 months
Rejection Criteria
Clotted or Hemolyzed
​Contaminated with IV or Hickman Line fluids
​Specimens that thaw storage or transport
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield Weekly​ ​Less than 2 hours Chromogenic assay /IL ACL TOP 550​
Test Information
​Do not order if the patient has received Coumadin for the past two weeks. If patient is on a stable dose of Coumadin (2 weeks), see Protein C Antigen, On Coumadin test (PROT-CM).
See Clinical Practice Guidelines for more information
Reference Range Information
Performing Location Reference Range
​Marshfield ​70-140 % 
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85303
Ordering Applications
Ordering Application Description
​Centricity ​Protein C Activity
​Cerner ​Protein C Activity
​COM ​Protein C Activity
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
*Platelet Poor Plasma 3.2% Citrated Blue Top Tube (BTT)​ 0.75 mL ​ 0.75 mL​ 0.5 mL ​
Collection Processing
​One 0.75 mL citrated Blue Top Tube (BTT) plasma aliquot.
If more than one coagulation test is ordered, a separate aliquot is needed for each test.
-Collect in Citrated Blue Top Tube (BTT)
-Citrate anticoagulant must be adjusted for HCT >55%
-Tube must be at least 90% full
-Invert completely 3-4 times (without shaking) to mix
*See Instructions for: Preparation of Platelet Poor Plasma
Specimen Stability Information
Specimen Type Temperature Time
​Plasma ​Frozen ​6 months
Rejection Criteria
Clotted or Hemolyzed
​Contaminated with IV or Hickman Line fluids
​Specimens that thaw storage or transport
Reference Range Information
Performing Location Reference Range
​Marshfield ​70-140 % 
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield Weekly​ ​Less than 2 hours Chromogenic assay /IL ACL TOP 550​
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​85303
For most current information refer to the Marshfield Laboratory online reference manual.