What color tube comes eighth in the order of draw?

• A. Dark green
• B. Royal blue w/ red stripe
• C. Discard tube
• D. Blood culture

Answer: (A)

In the context of the order of draw for collecting blood specimens, the color of the tube that comes eighth is actually dark green. This tube is primarily used for collecting specimens that require specific tests such as chemistry tests that analyze plasma. The dark green tube contains heparin, an anticoagulant that prevents blood from clotting, which is particularly necessary for certain laboratory analyses.

The order of draw is important because it helps to minimize contamination between different additive types. Each color-coded tube contains different additives that can affect test results if blood samples are drawn in the incorrect order. The other options have designated positions in the order of draw, with blood culture tubes typically drawn first, followed by other tubes, and the discard tube being used at specific times to clear the line or to prevent contaminants from interfering with test results.

Understanding the order of draw is critical for phlebotomists to ensure accurate lab results and effective patient care.