Which tube is drawn fifth in the order of draw?

The fifth tube drawn in the order of draw is represented by the color associated with the answer you selected. In the established order of draw for blood collection, certain tubes are designated based on their additive content and the potential for cross-contamination of test results.

For the correct choice, red plastic tubes typically do not contain any additives, making them ideal for serum testing. By placing them in the fifth position, it helps minimize the risk of any additives from earlier collected tubes that could interfere with subsequent tests. This is crucial for ensuring the integrity of the sample and obtaining accurate laboratory results.

The order of draw is established to prioritize the prevention of contamination, particularly by additives that might affect the results of specific tests. Other tube types, like the gold or tiger top, contain gel separators or clot activators and are addressed earlier to avoid any potential issues with tests that require serum.