What is the correct order of draw for venipuncture?

The correct order of draw for venipuncture is critical to prevent cross-contamination of additives found in the tubes that can affect laboratory test results. In this context, each tube's color corresponds to specific additives used for different tests.

The choice indicating green, lavender, and gray is correct because it follows the recommended sequence based on the additives in the tubes. Starting with the green tube, which contains heparin, helps to collect specimens that will be used for certain chemistry tests without the risk of contamination from other tube additives. Following this with the lavender tube, which contains EDTA, is appropriate as it prevents clotting and is used for hematology tests. Lastly, the gray tube, containing fluoride, is used for glucose testing among others and should be drawn last to avoid contamination from the previous additives.

Other potential orders listed may disrupt the testing parameters by introducing additives into subsequent samples, which could lead to erroneous results. Proper order of draw is a fundamental concept in phlebotomy and laboratory procedures, helping ensure the accuracy of diagnostic testing.