Interior of the tube is treated with an anti-adhesive agent, and the Blood Clot Activator is sprayed to accelerate the coagulation of the blood and shorten the inspection time. The separation gel is added into the tube, it has a good affinity with the PET tube, and indeed acts as a barrier. Generally, even in a common centrifuge, the separation gel can completely separate the liquid component (serum) and solid components (blood cells) in the blood and accumulate in the test tube to form a barrier. No oil droplets are produced in the serum after centrifugation, so the machine won’t be blocked.