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Test Code APCR Activated Protein C - Resistance

Specimen Type



Light blue top tube, 3.2% sodium citrate.

Preferred Volume

2.7 mL

Offsite Collection Instructions

Whole blood sample must arrive in the laboratory within three hours of specimen collection.


If transport time exceeds three hours, follow centrifugation instructions:

  • Samples must be centrifuged at >1500 x g for 10 minutes at room temperature.
  • Carefully remove the plasma from the cells using a plastic transfer pipette avoiding the buffy coat.
  • Aliquot removed plasma into 2 plastic tubes containing a minimum of 500 uL of specimen in each tube.
  • The plasma samples must then be frozen at -20ºC.
  • Once solidly frozen, they must be shipped on dry ice. Samples that have thawed in transit will be rejected.

Note: For clients who do not have access to dry ice DO NOT freeze the specimen. Follow the centrifugation instructions and send fresh plasma or send whole blood sample. It now becomes vital that the specimen arrives in the lab within three hours of collection.

UCMC Collection Instructions

Specimens may be collected and sent to the laboratory at any time.


Specimens may be collected and sent to the laboratory at any time. Testing is performed twice a week, Tuesdays and Thursdays, first shift.

Turnaround Time

5 days

STAT Availability

Not Available

Test Methodology


Additional Information

All 3.2 % sodium citrate light blue top tubes require a ratio of 9 parts blood to 1 part anticoagulant (example: a 3.0 mL tube requires 2.7 mL blood added to 0.3 mL of anticoagulant).
Determination of an abnormality in this functional test of Activated Protein C (APC) resistance should ordinarily be made prior to ordering Factor V Leiden genetic testing. APC Resistance may also be acquired. 

Note: Unlike tests for levels of Protein C, Protein S, or antithrombin, testing for APC resistance is expected to retain validity even in the setting of recent thrombotic events.

CPT Code


Minimum Volume

2.7 mL

Reference Range

>2.30; range effective 03/24/17

Fee Code