In the evacuated tube system, lavender or pink tubes should be collected in which position?

In the evacuated tube system, lavender or pink tubes should be collected in which position?

• A. Draw 7
• B. First
• C. Last
• D. Third

Answer: (A)

In the evacuated tube system, the sequence of draws is designed to prevent cross-contamination from one additive into the next. Lavender and pink tubes contain EDTA, an anticoagulant that binds calcium. If these tubes are collected earlier, EDTA can contaminate subsequent tubes and affect tests that require other anticoagulants or no additive, and it can alter calcium-dependent processes. To minimize that risk, EDTA tubes are placed at the end of the collection order, so they are the final draw. This preserves the integrity of the other tests and matches the practice of drawing lavender or pink tubes last.

In the evacuated tube system, the sequence of draws is designed to prevent cross-contamination from one additive into the next. Lavender and pink tubes contain EDTA, an anticoagulant that binds calcium. If these tubes are collected earlier, EDTA can contaminate subsequent tubes and affect tests that require other anticoagulants or no additive, and it can alter calcium-dependent processes. To minimize that risk, EDTA tubes are placed at the end of the collection order, so they are the final draw. This preserves the integrity of the other tests and matches the practice of drawing lavender or pink tubes last.