Sterile vacuum tubes suitable for Clinical Chemistry, Immunohematology and Microbiological Serology analyses. Serum tubes with integrated separator contain a barrier gel at the bottom of the tube. The relative density of this gel is between the blood clot one and the serum one during centrifugation, the barrier gel passes between the serum and the clot, forming a stable barrier that separates the serum from fibrin and cells. Furthermore, during centrifugation, the gel moves upwards forming a stable barrier that separates the serum from the cells.These tubes are clinically tested and validated for drug dosing and hormone determination. The combination between the color of the cap and the color of the rubber allows the healthcare worker to identify correctly the type of test tube even from a view of the rack from above (without consulting the label), minimizing the risk of error.