American Medical Certification Association (AMCA) Phlebotomy Practice Exam

When collecting blood for serum tests such as Comprehensive Metabolic Panel (CMP) or Basic Metabolic Panel (BMP), a gold or red-top tube is used because these tubes contain additives that facilitate the clotting process. The gold-top tubes often have a gel separator that allows for the easy separation of serum from the clotted blood after centrifugation, which is essential for accurate serum test results.

In contrast, hematological tests typically require lavender or purple-top tubes containing EDTA for anticoagulation purposes, meaning they must prevent blood from clotting. Blood gas tests often utilize green-top tubes with sodium heparin as an anticoagulant, and coagulation tests necessitate blue-top tubes that contain sodium citrate to help preserve samples for analysis. Thus, serum tests specifically utilize the gold or red-top tubes due to their property of providing a clear serum sample for evaluating various chemical components in the blood.