Which anticoagulant is commonly used in light blue top tubes?

The correct answer is sodium citrate, which is the anticoagulant commonly used in light blue top tubes. Sodium citrate functions as an anticoagulant by binding calcium ions in the blood, which is essential for the coagulation process. When blood is collected into a light blue top tube, the presence of sodium citrate helps prevent clotting and allows for accurate results in coagulation tests, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT).

Understanding the significance of this anticoagulant is crucial for ensuring that laboratory tests related to clotting factors are both accurate and reliable. Each type of tube has specific additives that serve distinct purposes, and sodium citrate's role in coagulation testing is well-established in the field of phlebotomy.