Which anticoagulant is found in the blue top tube?

The blue top tube contains sodium citrate, which is a type of anticoagulant specifically used for coagulation testing. Sodium citrate works by binding calcium ions in the blood, which are essential for the coagulation process. This allows for accurate measurement of clotting factors and helps in diagnosing various bleeding disorders and assessing the body's ability to form clots.

In laboratory settings, the presence of sodium citrate in the blue top tube makes this tube ideal for tests like PT (prothrombin time) and APTT (activated partial thromboplastin time), as it prevents the blood from clotting. This characteristic ensures that the sample remains in a liquid state, thereby providing reliable results.

Other anticoagulants mentioned do not belong in the context of the blue top tube. Heparin, for instance, is found in green top tubes, while EDTA, which is used for hematology tests, is in lavender top tubes. Lithium heparin is associated with plasma chemistry tests and is found in green top tubes as well. Each tube is specifically designed for certain tests, which is crucial for accurate laboratory analysis.