What type of tube is typically used for coagulation tests?

The blue tube is specifically designed for coagulation tests due to its additive properties. This tube contains sodium citrate, which acts as an anticoagulant that binds calcium ions in the blood sample. By doing so, it prevents the blood from clotting during the testing process. This is crucial for accurately measuring various aspects of coagulation, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT), which are essential for assessing bleeding disorders, monitoring anticoagulant therapy, and evaluating the blood's ability to clot properly.

Understanding the role of the additive in the blue tube helps reinforce the significance of using the correct tube for specific laboratory tests to ensure reliable and valid results.