Which blood collection tube is commonly used for hematology tests?

The purple blood collection tube is commonly used for hematology tests due to the additive contained within it, which is ethylenediaminetetraacetic acid (EDTA). EDTA acts as an anticoagulant, preventing blood from clotting, which is essential for accurate hematology testing. This type of testing often includes complete blood counts (CBC) and other assessments that require unhindered blood flow through the sample. The use of a tube with the appropriate anticoagulant ensures that the cellular components of the blood remain intact and can be properly analyzed.

In contrast, the other tubes have different uses based on their additives. The light blue tube contains sodium citrate, which is primarily used for coagulation studies. The green tube is used for tests requiring heparin as an anticoagulant, often in chemistry assays. The red tube is generally used for serum tests where no anticoagulant is needed, allowing the blood to clot and the serum to be separated. Therefore, the properties and intended uses of the purple tube make it the preferred choice for hematology tests.