How do laboratory centrifuges separate red blood cells from blood plasma?

Laboratory centrifuges separate red blood cells from blood plasma by utilizing centrifugal force to accelerate the natural process of sedimentation.12

When blood is placed in a centrifuge, the device spins the sample at high speeds, creating a force that acts as a substitute for gravity but is significantly stronger. Because red blood cells are denser than the surrounding plasma, they are pushed outward toward the periphery of the spinning vessel.13

In a typical laboratory setting, this process is performed using a bottle centrifuge, where test tubes are mounted on a rotor. As the rotor spins, the denser red cells migrate to the bottom of the tube, forming a sediment, while the lighter plasma remains as the supernatant fluid above. This separation occurs because the net force acting on the particles is the difference between the centrifugal field and the liquid's buoyancy, causing denser components to move away from the center of rotation more rapidly than they would under normal gravitational conditions.312