One 7.5 mL serum separator tube (SST). Also acceptable: One 4.5 light green top tube (lithium heparin) (PST). Patient should fast 8-12 hours if a fasting glucose is needed; otherwise, a non-fasting specimen is acceptable. Patient should avoid exercising forearm before collection, which can cause an elevation in potassium level. Do not draw from a limb receiving an intravenous infusion.
Handling:
Allow to clot. Centrifuge SST within on hour of collection and transport in original tube. Centrifuge green top tube within 30 minutes of collection and separate plasma into a plastic tube for transport. Refrigerate.
Stability:
6 days refrigerated.
Standard Volume:
2 mL serum or plasma.
Minimum Volume:
1 mL serum or plasma.
Transport:
Refrigerated.
Rejection Criteria:
Gross hemolysis, specimen left in contact with cells beyond 3 hours, tubes other than those specified.