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

A blood collection tube with a yellow stopper is primarily used for collecting blood cultures. The yellow top typically contains additives such as sodium polyanethol sulfonate (SPS) or other suitable preservatives that inhibit the growth of contaminants while promoting the growth of microorganisms. This makes it particularly useful for detecting infections in the bloodstream, as it allows for the proper cultivation of bacteria or fungi present in the blood sample.

Testing for blood cultures is crucial in diagnosing infections, especially in cases where a systemic infection is suspected. The proper use of these tubes helps ensure accurate results in identifying pathogens, which can guide appropriate treatment plans for the patient.