Specimen Requirements

Riverside Inpatient or Riverside Campus draw sites:

Testing must be performed within 4 hours of draw if submitting unprocessed whole blood.

Draw  2 full, light blue-top (citrate) tube; and send citrated whole blood. Invert several times to mix blood. Forward unprocessed whole blood promptly at ambient temperature only. Do not refrigerate.

Note:  1. This assay requires its own specimen.

2. Gross hemolysis, icterus, and lipemia may affect results.

3. Indicate whole blood on request form.

4. Label specimen appropriately (whole blood).

Outpatient/Outreach Clients

Plasma

Draw 2 full, light blue-top (citrate) tube. Spin down, remove plasma, spin plasma again, and place 1 mL of citrated platelet-poor plasma into 2 plastic vials each containing 1.0 mL. (Glass vial is not acceptable.)   Pour-off vials should be no more than 2/3 full. Send specimen frozen.

Note:  1. This assay requires its own specimen.

2. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.

3. If patient is being treated with Coumadin, this should be noted on request.  Coumadin will lower   Protein C

NOTE: Two aliquots required due to possible reflex to Protein C Antigen.