Final answer:
It is false that a red tube is used for STAT electrolytes. A green-topped tube containing heparin, which prevents blood clotting, is typically used for such immediate tests, not the red-topped tubes which have no anticoagulants.
Step-by-step explanation:
The statement that a red tube is used for STAT electrolytes is false. In phlebotomy, tubes used for blood draws come in various colors, with each color corresponding to different tests and additives within the tubes. A red-topped tube typically contains no anticoagulants and is used for serological tests and blood donations. For STAT electrolytes, which require immediate processing and analysis, tubes with other additives are generally used, such as a green-topped tube that contains heparin. Heparin prevents clotting and allows for the quick preparation of plasma for electrolyte analysis, which is crucial for STAT or 'immediate' testing scenarios.