Centrifugation is an important sample separation and analysis technology, which is widely used in medical laboratories and related fields. Centrifugation is to separate, concentrate, extract and prepare samples by centrifugal force, using the difference of sedimentation coefficient, buoyancy and density of centrifuged samples, and analyze and determine the molecular weight and purity of biological macromolecules. According to its working mode, it can be divided into centrifugal filtration, centrifugal sedimentation (or clarification) and centrifugal separation.



The design principle of the centrifuge is to use the centrifugal force produced by the rotating head to speed up the settling speed of the sample particles and separate the different settling coefficient or buoyancy density substances in the sample. Besides the rotational speed (Revolved per minute, r/min) and the radius of the centrifuge (turning head), the factors determining the centrifugal force are also related to the forces (gravity, buoyancy, friction) exerted on the particles in the rotational motion. The direction of the centrifugal force is perpendicular to gravity, so the relative centrifugal force (rcO) is often used. That is, relative to the centrifugal force exerted by gravity on a rotating particle, the acceleration g (980cm/s) of gravity is used as a measure, also known as "g-Force". The expression is: RCF = o) ~/980.


The key of centrifugal technology is how to determine the centrifugal force, rotational speed and centrifugal time according to the properties of sample particles and media and the technical parameters of rotor. The settling or separating rate of particles (cells, organelles and macromolecules in general) depends on centrifugal force, particle size, shape and density, and the density and viscosity of settling media.


According to the use, rotational speed and function configuration, several types of centrifuges commonly used in medical laboratories can be produced with different rotational speed of centrifuge different centrifugal force, different uses.


The low-speed Cen trifuge is designed with large capacity (12L), which is mainly used for the separation and preparation of cells, serum, plasma and batch samples, and plays a greater role in the field of biopharmaceuticals; the high-speed cen-trifuge is mainly used for some subcellular structures, nucleic acids, proteins, plasmids. Ultracentrifuge. ~ 0 is suitable for isolation and purification of viruses, nucleic acids and proteins, and analytical ultracentrifuge can be used for further analysis and research.


In recent years, a new type of centrifuge called Universal Lab - oratory centrifuge has been introduced into medical lab oratory, which meets the needs of experimental technology in molecular biology, cell biology and other related fields. Its characteristic is that it takes into account the performance of low speed machine and high speed machine, micro and large capacity, but it is small in volume, light in weight, small in power consumption and easy to operate; the highest speed of common models is more than 13O00r/min, and the starting speed of individual models is less than 20O00r/min, and the maximum RCF is generally up to 20000~g, and the maximum RCF of individual models is up to 60000xg; The maximum cardiac capacity is up to 3 000ml.