Preferred: Serum, one 5.0 mL Gold (SST) or 7.0 mL red top tube
Also acceptable: EDTA Plasma AND either one 5.0 mL gold (SST), 7.0 mL red top tube or 3.0 mL mint green (PST) top tube.
NOTE: Serum is the preferred specimen for measuring PTHI. EDTA plasma may be accepted only if a separate serum or lithium heparin plasma specimen is provided for testing calcium. The EDTA plasma must be drawn at the same time of collection as the serum/lithium heparin plasma tube. Testing will not be performed if these two tubes are not drawn at the same time of collection.