What is the primary use of the light blue tube in phlebotomy?

The primary use of the light blue tube in phlebotomy is for coagulation studies. This tube contains sodium citrate, an anticoagulant that helps preserve the blood sample for accurate testing of various clotting factors. Coagulation tests, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT), require a precise ratio of blood to anticoagulant, which is why the light blue tube is specifically designed for these tests.

It is important to use the light blue tube correctly because other tubes contain different additives that could interfere with coagulation testing. For example, the presence of gel or other anticoagulants in other tubes would not provide the necessary environment for accurate coagulation assessment. This specificity is crucial in medical testing and patient care, ensuring reliable results for conditions related to blood clotting.