Necessary Information

If the patient’s hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted.

Specimen Required

Patient Preparation: Ideally, the patient should not be on anticoagulant therapy. Avoid warfarin (Coumadin) therapy for two weeks prior to the test and heparin, direct Xa, and thrombin inhibitor therapies for about three days prior to testing. Do not draw from an arm with a heparin lock or heparinized catheter.

Specimen Type: Citrated plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL Plasma

Collection Instructions:

1. Draw blood in a blue-top tube containing 3.2% buffered sodium citrate.

2. Mix immediately by gentle inversion at least six times to ensure adequate mixing of the anticoagulant with the blood.

3. Centrifuge for 10 minutes and remove 2/3 of the plasma using a plastic transfer pipette, being careful not to disturb the cells.

4. Transfer to a plastic transport tube, cap, and centrifuge again for 10 minutes.

5. Use a second plastic pipette to remove the plasma, staying clear of the platelets at the bottom of the tube.

6. Transfer the plasma into a plastic vial and freeze immediately.

7. Send frozen.

Note: Critical frozen. Separate specimens must be submitted when multiple tests are ordered.