centrifughi

centrifughi, also known as centrifuges, are laboratory devices that use centrifugal force to separate components of a mixture based on density. They achieve this by spinning samples, often contained in tubes or vials, at high speeds in rotors. The separation results from differences in sedimentation rates of the constituents when subjected to rapid rotation.

Common types include microcentrifuges for small-volume samples, refrigerated models to control temperature-sensitive materials, and ultracentrifuges capable of very high speeds. Rotors can be fixed-angle, where tubes are held at a constant angle, or swinging-bucket, where tubes rotate to a horizontal position during operation. The separation efficiency is described by the relative centrifugal force (RCF), calculated as RCF = 1.118×10^-5 × r × (rpm)^2, where r is the rotor radius in centimeters and rpm is the rotation speed.

Centrifughi are widely used in biology, biochemistry, and clinical laboratories. Applications include isolation of DNA, RNA, and proteins, preparation of plasma or serum, cellular fractionation, and purification of macromolecules. They also play a role in industrial processes such as clarification of liquids and particle separation.

Safety and operation require balanced rotors, proper rotor matching to tubes, temperature control when needed, and adherence to manufacturer limits for speed and duration. Rotor failure and sample overheating pose risks, thus routine maintenance and following protocols are essential. The Svedberg unit (S) is used in sedimentation analysis, reflecting the historic development of analytical ultracentrifugation and the measurement of macromolecular size and shape.