Specimen Requirements

Blood and plasma are required for this test.

Specimen must arrive within 24 hours of draw.

Blood for Platelet Count

Draw blood in a lavender-top (EDTA) tube(s), and send 2 mL of EDTA whole blood refrigerated. For pediatric specimen, draw a full, lavender-top (EDTA) MICROTAINER®. Label specimen with patient’s name (first and last), date of birth, date and time of draw, and phlebotomist’s initials.

Clotted specimens are not acceptable.

Plasma for all Other Tests

 Draw blood in a full, blue-top (3.2% sodium citrate) tube. Invert 6 times to mix blood, and place tube in crushed ice. Do not draw specimen from an arm with a heparin lock or heparinized catheter. Centrifuge specimen for 10 minutes at 3,000 rpm, remove plasma, and place 0.5 mL of citrate platelet-poor plasma in plastic vial. (Glass vial is not acceptable.)  Label specimen with patient’s name (first and last), date of birth, date and time of draw, and phlebotomist’s initials.

Plasma for PTT should be drawn 1 hour prior to next dose of heparin if heparin is being given by intermittent injection; not applicable for patients on continuous heparin infusion therapy.

The following specimens will rejected:

Clotted or hemolyzed specimen

Hematocrit >55%

Incorrect anticoagulant

Overfilled or underfilled tube

Specimen stability:   4 hours when kept uncapped at room temperature

                                    If unable to complete testing within 4 hours of collection, the plasma should be removed and frozen

                                    in a capped plastic tube at ≥-20°C for up to 2 weeks. 

Minimum volume:  0.5 mL