Specimen Requirements

The only acceptable specimen is a lithium heparin tube with or without gel barrier. The tube must be completely full. Keep the specimen anaerobic (do not transfer). Venipuncture specimens drawn at satellite locations for ionized calcium analysis must be tested within six hours of collection and should be kept refrigerated after collection. Exception: Infant specimens may be obtained from heel stick into a full, dark green-top microtainer. Every effort should be made to keep collection time for these infant specimens under five minutes.