Which type of tube is recommended for coagulation tests?

The light blue top tube is specifically designed for coagulation tests because it contains sodium citrate as an additive. Sodium citrate acts as an anticoagulant, binding calcium in the blood and preventing clotting during the testing process. This is crucial for obtaining accurate results in coagulation analysis, such as PT (prothrombin time) and aPTT (activated partial thromboplastin time), which rely on the blood remaining in a liquid state during testing.

Using the appropriate tube is essential, as each type has specific additives that can influence test outcomes. For example, the green top tube contains heparin, which is suitable for certain chemistry tests but not for coagulation tests where a different anticoagulant is necessary. The red top tube lacks any additives and does not prevent clotting, making it unsuitable for coagulation tests. The purple top tube, typically containing EDTA, is meant for hematology tests and can interfere with coagulation assays. Therefore, utilizing the light blue top tube ensures proper sample collection and accuracy in coagulation testing.