Question

In venipuncture, which type of tube should NEVER be drawn first?

1) Red top tube
2) Lavender top tube
3) Blue top tube
4) Green top tube

Answer 1

In venipuncture, a 2) Lavender top tube should not be drawn first due to the potential for contaminating other specimens with its EDTA content. The standard order usually begins with a blue top tube to avoid test result inaccuracies.

Step-by-step explanation:

In venipuncture, the tube that should NEVER be drawn first is the Lavender top tube (2). This is because the lavender top tube contains EDTA which can contaminate the specimens in other tubes if the order of draw is not followed. To ensure the accuracy of test results and prevent cross-contamination, there is a standard order of draw that should be followed, which generally starts with the blue top tube, specifically when conducting coagulation tests since it contains sodium citrate. The order of draw is critical in ensuring the reliability of laboratory results, and not adhering to it can result in diagnostic errors.