Protein C-Functional

Test Code

117705

Alias/See Also

Functional Protein C, Protein Activity

CPT Codes
85303

Preferred Specimen

Plasma

Minimum Volume

1mL

Instructions

Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate.(1) Evacuated collection tubes must be filled to completion to ensure a proper blood-to-anticoagulant ratio.(2,3) The sample should be mixed immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood. A discard tube is not required prior to collection of coagulation samples unless the sample is collected using a winged (butterfly) collection system. With a winged blood collection set a discard tube should be drawn first to account for the dead space of the tubing and prevent under-filling of the evacutated tube.(4,5) When noncitrate tubes are collected for other tests, collect sterile and nonadditive (red-top) tubes prior to citrate (blue-top) tubes. Any tube containing an alternative anticoagulant should be collected after the blue-top tube. Gel-barrier tubes and serum tubes with clot initiators should also be collected after the citrate tubes. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. Print and use the Specimen Collection Bulletin as a tube-filling guide.

Transport Container

Blue-top (sodium citrate) tube

Transport Temperature

Freeze

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis; clotted specimen; specimen that have thawed in transit; improperly labeled specimen.

Methodology
A specific enzyme extracted from the venom of agkistrodon c. contortrix is useds to activate PC in the patient sample. All other factors required for normal aPTT are supplied in the reagent. The activated protein C inhibits factors V and VIII in the reagent and the resultant prolongation of the aPTT-based clotting time is proportional to plasma PC activity.

Setup Schedule

Daily 1st and 3rd shift

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.