One 7.5 mL serum separator tube (SST). Also acceptable: One 4 mL green top tube (heparin). Do not draw from an arm receiving an intravenous infusion. Patient should avoid exercising forearm before collection, which can cause an elevation in the potassium level.
Handling:
Centrifuge SST and transport in original tube. Centrifuge green top tube within 30 minutes of collection and separate plasma into a plastic tube for transport. Refrigerate.
Standard Volume:
2 mL serum or plasma.
Minimum Volume:
0.5 mL serum or plasma.
Transport:
Refrigerated.
Rejection Criteria:
Gross hemolysis; tubes other than those specified.