CALCIUM, IONIZED

Tourniquet use: Avoid tourniquet use (preferred) or apply the tourniquet briefly and release it before blood collection to avoid false elevation of calcium levels. Sample collection: Use a serum separator tube (SST) to collect the sample. Proper clotting: Allow the sample to clot fully at room temperature for about 30 minutes. Avoid hemolysis: Minimize trauma to the sample to prevent interference from hemolysis. Proper handling: Separate serum from cells within 1 hour of collection to prevent calcium binding. Sample volume: Ensure adequate sample volume for accurate analysis. Avoid air exposure to prevent changes in pH.