American Medical Certification Association (AMCA) Phlebotomy Practice Exam 2026 - Free Phlebotomy Practice Questions and Study Guide

The royal blue tube top is specifically designed for trace element testing, including aluminum. This tube is devoid of any additives that could potentially contaminate the sample, which is crucial for accurate measurement of trace metals in blood. When testing for elements such as aluminum, it’s vital to eliminate any possibility of contamination from the tube itself, which is why the royal blue tube is the preferred choice in this instance. Moreover, this tube often has a specific designation for metal analysis, enhancing its appropriateness for tests requiring the detection of trace levels of metals.

In contrast, other tube types serve different purposes. For example, the red tube top usually contains no additives and is often used for serum tests, while the yellow tube top is commonly associated with blood culture tests or specific serological tests. The purple tube top, or lavender top, is typically used for complete blood counts and other hematology tests and contains an anticoagulant, which is not suitable for metal analysis due to the potential for interfering with the results. Thus, the royal blue tube top is indeed the correct choice for testing for aluminum.