In medical testing, centrifuges are often used as medical equipment for separating serum, plasma, depositing proteins, or for urine sediment examination. The use of centrifuges can make a mixture of the suspended particles in the rapid precipitation, in order to separate the specific gravity of a variety of substances of different components. Centrifuge is the use of centrifuge rotor rotating at high speed to produce a strong centrifugal force, forcing particles in the liquid to overcome the diffusion and accelerate the rate of precipitation, with different coefficients of sedimentation of the samples and buoyancy density of the material separation. For particles smaller than a few microns, such as viruses or proteins, which are in a colloidal or semi-colloidal state in the solution, the sedimentation process can not be observed by gravity alone. This is because the smaller the particle, the slower the sedimentation and the more serious the diffusion phenomenon. Therefore, a centrifu…