separate SST tube for ionized calcium and adhere a piece of labeling tape over the top of the tube with the following written on it “Ionized Calcium -DO NOT OPEN.
Specimen Retention
Centrifuge and send unopened gel-barrier tube with vacuum intact. It is critical that the vacuum not be disrupted. Exposure of the serum to room air causes a loss of carbon dioxide to the atmosphere. This changes the sample pH and can prevent the lab from measuring the ionized calcium. To ensure that testing can be performed, send a separate tube for ionized calcium and adhere a piece of labeling tape over the top of the tube with the following written on it IONIZED CALCIUM-DO NOT OPEN.
