Which color stopper tube is typically used to collect a blood specimen for a complete blood cell count (CBC)?

• A. Green
• B. Blue
• C. Red
• D. Lavender

Answer: (D)

Verified step by step guidance

1. Understand that different blood collection tubes are color-coded based on the additives they contain, which affect the type of tests that can be performed on the blood sample.
2. Recall that a Complete Blood Cell Count (CBC) requires whole blood with anticoagulants to prevent clotting, so the blood cells remain intact for analysis.
3. Identify that the lavender (or purple) stopper tube contains EDTA (ethylenediaminetetraacetic acid), an anticoagulant that preserves the shape and size of blood cells, making it ideal for CBC tests.
4. Compare the other options: green stopper tubes contain heparin (used for plasma chemistry tests), blue stopper tubes contain sodium citrate (used for coagulation studies), and red stopper tubes usually contain no anticoagulant (used for serum tests).
5. Conclude that the lavender stopper tube is the correct choice for collecting blood specimens for a CBC because it prevents clotting and preserves blood cells for accurate counting.