Which type of blood tube is typically used for the collection of a complete blood count (CBC)?

The lavender-top tube is specifically designed for the collection of blood samples intended for a complete blood count (CBC). This tube contains ethylenediaminetetraacetic acid (EDTA), an anticoagulant that prevents clotting in the blood sample. The use of EDTA is crucial for CBC testing as it maintains the integrity of the blood cells, allowing for accurate analysis of components such as red blood cells, white blood cells, and platelets.

In contrast, the green-top tube typically contains heparin, which is used for various tests but not usually for a CBC since it may affect the morphology of cells in the analysis. The red-top tube does not contain any anticoagulant, making it suitable for serum tests but not for CBCs, as clotting would alter the results. The yellow-top tube is used for specific tests such as blood cultures or for serum in certain types of chemistry tests but is not appropriate for a CBC due to the lack of an anticoagulant. Therefore, the lavender-top tube is the standard option for collecting blood samples for CBC analysis.