Specimen Requirements

Container/Tube Type: 

Light Blue (Citrate)

Collection Information: 

Collect blood in a blue top tube, tube must be full for testing to be performed.

Transport Information: 

1. Centrifuge, transfer all plasma into a plastic vial, and centrifuge plasma again.
2. Aliquot 1.0 mL of plasma into a plastic vial leaving 0.25 mL in the bottom of centrifuged vial.
3. Freeze plasma immediately (no longer than 4 hours after collection) at -20° C or, ideally, at ≤-40° C.

Minimum Sample Volume: 

0.5 mL of citrate plasma

Remarks: 

1. If the patient is being treated with Coumadin, this should be noted. Coumadin will lower protein C.
2. Heparin (unfractionated or low molecular weight) 2 U/mL or more may interfere with this assay.