For the 3rd draw, which color tube is typically used?

• A. Green or tan
• B. Gold
• C. Red
• D. Light Blue

Answer: (B)

Understanding the order of draw involves knowing how additives and separation affect the sample you need. After the light blue tube (used for coagulation tests), the next tube commonly drawn for serum chemistry panels is the serum separator tube with a clot activator and gel, which is the gold top. The clot activator speeds up clotting, and the gel forms a barrier between serum and the blood cells once centrifuged. This combination gives you clean, well-separated serum suitable for a wide range of chemistry and immunology tests, which is why this tube is typically used third. Red tops exist for additive-free serum, but they lack the gel barrier and clot activator, so the gold top is preferred when serum is required quickly and reliably.