Specimen Requirements

Draw blood in green-top (lithium heparin) tube. Serum is also acceptable, but not preferred. A morning specimen is preferred. Hemolyzed specimen is not acceptable for phosphorus. Spin down and send 1 mL (minimum 0.5 mL) of lithium heparin plasma. Keep specimen refrigerated at 2 - 8° Celsius. If tube will not arrive in the lab within eight hours of collection, send specimen frozen in a pour off tube.