tsentrifuugid

Tsentrifuugid are laboratory instruments that use high-speed rotation to generate centrifugal force, enabling the separation of mixtures according to density or size. They consist of a motor-driven rotor housed in a sealed chamber, with tubes or vials placed in slots. Rotors can be fixed-angle or swinging-bucket, and many models are refrigerated to protect heat-labile samples. Separation efficiency depends on speed, time, rotor radius and rotor design; performance is commonly described by revolutions per minute (rpm) and relative centrifugal force (RCF, in g).

RCF can be calculated roughly as RCF = 1.118×10^-5 × r × (rpm)^2, where r is the rotor radius in centimeters. Types include microcentrifuges for small-volume tubes, benchtop and floor-model centrifuges, and ultracentrifuges capable of speeds above 100,000 rpm. Centrifuges are used in analytical work to study sedimentation properties and in preparative work to separate and purify biological particles.

Common applications include differential centrifugation and density-gradient centrifugation to isolate components such as organelles, nucleic acids, proteins, lipids, or subviral particles. Safety considerations include rotor-specific tube compatibility, proper balancing of loads, avoiding rotor over-speed, and regular maintenance of the rotor and seals. The Svedberg unit (S) is a historical measure of sedimentation velocity used in ultracentrifugation to describe macromolecules.