Which color tube is typically used for collecting blood for a complete blood count (CBC)?

The lavender or purple top tube is typically used for collecting blood for a complete blood count (CBC) because it contains EDTA, an anticoagulant that prevents the blood from clotting. This is important for a CBC as the test requires whole blood to analyze various components such as red blood cells, white blood cells, and platelets. The use of EDTA preserves the cellular elements of the blood, ensuring accurate and reliable results.

In contrast, the green top tube, which contains heparin, is often used for different types of tests, including plasma chemistry tests. The red top tube, which does not contain any additives, is used for serum tests and is not ideal for tests like a CBC that require whole blood. The yellow top tube, typically used for certain types of blood cultures and other specific tests, is not suitable for a CBC either. This specificity in additives and tube types is vital for ensuring the integrity of the sample and the accuracy of test results.