Sign in →

Epic Code LAB489 Protein C Activity

Important Note

There is currently a nationwide shortage of this tube. Please take steps to ensure specimen integrity to reduce recollection. Specimen Tube Shortage (link)

Test Name Alias

Protein C Activity | 8381

Interface Order Alias


Quick Collect


Clinical Information

Protein C is a vitamin K dependent plasma protein which plays an important role in the anticoagulant regulatory mechanisms, specifically as it relates to thrombin generation. Activated protein C with its cofactor, protein S, regulates the coagulation system by proteolytic cleavage and inactivation of activated factors Va and VIIIa.


Intended Use: The functional protein C activity assay is used for the evaluation of patients suspected of having inherited or acquired protein C deficiency. May be used for the evaluation of a thrombophilia risk evaluation in patients with a personal or family history of a thrombotic event.

Collection Instructions

Container(s): 3.2% Na Citrate Tube (blue top)

Preferred Volume to Collect: 2.7 mL (full tube)

Minimum Volume to Collect: 1.8 mL (full tube)

Capillary collect ok: No

Microtainer acceptable: No


Collection Instructions:

Processing Instructions (Laboratory, Outpatient or Off-site collection)

Processed Specimen: Platelet Poor Plasma


Centrifuge/Spin: Yes

Aliquot: Yes


Processing Instructions:

  • Detailed instructions (link): Preparing Platelet Poor Plasma
  • Separate plasma into 2 – 3 aliquots, minimum of 0.5 mL each.
  • Freeze aliquots in plastic transport tubes immediately.

Transport Temperature:

  • Ambient (up to 1 hour in whole blood state)
  • Frozen (plasma only >1 hours)

Rejection Criteria

  • Hemolysis
  • Specimen has been thawed

Specimen Stability

Ambient: 1 hour

Frozen: 2 months

Laboratory Retention: 2 months

Test Frequency

Monday-Friday, usual TAT is 1-4 days.

Reference Range

Adult: 75 – 150 %

Pediatric reference ranges have not been established

Performing Department


Performing Department Laboratory Location

Corewell Health Reference Laboratory, Grand Rapids, MI


Chromogenic Assay



CDM Code


Epic Test ID



Protein C Activity: 27818-4

Mayo Access Code


Reviewed Date