For drawing blood for a complete blood count (CBC), which color tube is used?

The lavender tube is specifically designed for collecting blood samples for a complete blood count (CBC). This is due to the fact that it contains EDTA (ethylenediaminetetraacetic acid), an anticoagulant that prevents blood from clotting. The presence of EDTA is crucial in maintaining the integrity of the blood sample for analyses that require the cells to remain in a liquid state.

In contrast, other colored tubes contain different additives suited for various tests. The red tube typically lacks any anticoagulants and is used for tests that require serum, while the blue tube usually contains sodium citrate for coagulation studies. The green tube, containing heparin, is used for tests requiring plasma samples but is not suited for a CBC, which needs the blood to be untreated to allow for cellular analysis. Thus, the lavender tube is the appropriate choice for a CBC because it preserves the cellular components necessary for accurate results.