Myeloperoxidase (MPO)

Collect whole blood using venipuncture techniques. Gently mix the blood with the anticoagulant by inverting sample tube several times (do not shake).

Place freshly collected blood samples on ice or in a refrigerator 2°C to 8°C immediately, and store them at 2°C to 8°C until separation. Plasma should be physically separated from cells within two hours of collection by centrifugation at 2°C to 8°C. If a refrigerated centrifuge is not available, chill the centrifuge carrier in the refrigerator before use until cold.

Special precaution needs to be taken to ensure transfer of the plasma layer to a polypropylene (not glass) tube while avoiding carryover of any red blood cells or buffy coat white cells. The plasma samples thus prepared may be refrigerated at 2°C to 8°C for five days.

If plasma samples are prepared by gel based vacuum tubes, the plasma samples need to be transferred to separated tubes from the top of the gels immediately after the centrifugation.

Increased levels of MPO may be observed if the plasma samples are left on the top of the gels for more than eight hours before transferring to separate tubes.

Refrigerate.

Specimen type other than heparinized plasma or EDTA plasma; plasma samples left on top of gels for more than eight hours before transferring to separate tubes; specimen received at room temperature