One 7.5 mL serum separator tube (SST). Also acceptable: One 4 mL green top tube (heparin) or 4 mL plasma separator tube (PST).
Handling:
Allow to clot, centrifuge and separate serum or plasma from cells and pour into plastic vial immediately. Refrigerate. Serum left in contact with cells for more than 3 hours may cause spurious results.
Standard Volume:
2 mL serum or plasma.
Transport:
Refrigerated.
Comments:
Avoid drawing from arm receiving intravenous transfusion. Patient should avoid exercising forearm before collection, which can cause an increase in potassium levels.
Rejection Criteria:
Gross hemolysis; freeze/thawing; serum on cells more than three hours.