When drawing blood for a CBC, which color tube should be used?

The correct choice for drawing blood for a Complete Blood Count (CBC) is the lavender tube. This tube contains EDTA, an anticoagulant that prevents blood from clotting and preserves the cells for analysis. EDTA is specifically recommended for hematological studies, including a CBC, because it maintains the integrity of the blood components and ensures accurate results.

The other colored tubes are associated with different additives and purposes. The red tube, for example, is typically used for serum tests, as it does not contain an anticoagulant and allows for the blood to clot. The green tube contains heparin, which is also an anticoagulant but is more suitable for specific tests that require plasma rather than whole blood cell counts. The blue tube contains sodium citrate, which is used primarily for coagulation studies and not for a CBC. Thus, lavender is the right choice for a CBC due to its specific function in preserving blood cell morphology and function for accurate laboratory results.