Which tube is seventh in the order of draw?

The correct answer is light green, as it is positioned seventh in the standard order of draw for blood collection tubes. Following the established order of draw minimizes the risk of contamination and ensures the integrity of the test results. The light green tube, which contains a lithium heparin anticoagulant, is typically used for plasma testing.

Understanding the order of draw is crucial for phlebotomists because different additives in the tubes can affect the tests being performed. By adhering to this specific sequence, phlebotomists can prevent cross-contamination of the additives from one tube to another, which could lead to erroneous lab results.