What anticoagulant is typically found in the light blue top tube?

The light blue top tube is commonly used for coagulation studies, and it contains sodium citrate as its anticoagulant. Sodium citrate works by binding calcium ions in the blood, which are essential for the coagulation process. By removing calcium, sodium citrate effectively prevents the blood from clotting.

This property makes the light blue top tube particularly valuable for tests that require the assessment of the coagulation pathway, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT).

In contrast, other anticoagulants serve different purposes or are used for different tests. Heparin and EDTA, found in green and lavender top tubes respectively, are used for other types of blood tests; heparin is often utilized in tests requiring plasma, while EDTA is predominantly used in hematology for complete blood counts. Citrated phosphate is not a standard anticoagulant used in blood collection tubes, which further emphasizes the unique use of sodium citrate in the light blue top tube.