Which type of blood collection tube is typically used for hematology tests?

The lavender (purple) top tube is typically used for hematology tests because it contains EDTA, an anticoagulant that prevents blood from clotting. This is essential for hematology tests, such as complete blood counts (CBC), where whole blood is needed for accurate analysis of blood cells. The EDTA preserves the cellular components of the blood, allowing for reliable results when counting red and white blood cells and evaluating hemoglobin levels.

In contrast, the other tubes serve different purposes: the red top tube often contains no additives or may have a clot activator, making it suitable for serum tests rather than whole blood tests. The green top tube contains heparin, which is mainly used for chemistry tests where plasma is required. The gray top tube typically contains sodium fluoride and potassium oxalate, which is used for glucose testing and not appropriate for hematology assessments.