Centrifugation is the separation, concentration, extraction and preparation of samples by the centrifugal force, using the difference in sedimentation coefficient, buoyancy and density of the sampled material, and the determination of the molecular weight and purity of the biomacromolecules. According to its working mode, it can be divided into centrifugal filtration, centrifugal sedimentation (or clarification) and centrifugal separation.
The design principle is to use the centrifuge rotor drive rotation of the centrifugal force field generated by the sample up the settling velocity of the particles, the difference in the sample or a different buoyant density sedimentation coefficients and separate substances. In addition to the revolved per minute (r/min) and centrifugal (rotary) radius, the factors that determine the magnitude of the centrifugal force are also related to the effects of the forces (gravity, buoyancy, friction) of the particles in the rotational motion. The direction is perpendicular to the gravity, so the relative centrifugal force (R0) is used, that is, the centrifugal force acting on the rotating particles with respect to gravity, and the gravitational acceleration g (980 cm/s) is used as the magnitude, also called “g-Forceâ€. ", the expression is: RCF = o) ~ / 980.
The key to centrifugation is how to determine the centrifugal force, speed and centrifugation time settings based on the nature of the sample particles and media and the technical parameters of the rotor. The rate of settling or separation of particles (collectively referred to as cells, organelles, and macromolecules) depends on the centrifugal force, the size, shape and density of the particles, and the density and viscosity of the settling medium. According to the use, speed, and functional configuration, there are several types of centrifuges commonly used in medical laboratories. Centrifuges with different speeds produce different centrifugal forces and have different uses.
The low-speed model has a large capacity (Large capacity centrifuge, ≥12L), which is mainly used for the separation and preparation of cells, serum, plasma and batch samples, and plays a major role in the field of biopharmaceuticals;
High speed cen-trifuge is mainly used for the separation and preparation of certain subcellular organelles, nucleic acids, proteins, plasmids and bacteria; and ultracentrifuges (Ultracentrifuge). ~0 is suitable for the separation and purification of viruses, nucleic acids and proteins, and further analytical studies can also use analytical ultracentrifuges.
In recent years, a model called "Universal Lab-oratory Centrifuge" has entered the medical laboratory, and has been adapted to the needs of experimental techniques in related fields such as molecular biology and cell biology. Received the attention of laboratory workers. It is characterized by low speed and high speed machine, small and large capacity performance, but small size, light weight, low power consumption and easy operation; the maximum speed of common models is ≥13000r/min, and the individual models exceed 20000r/min. The starting speed can be as low as 100r/min; the maximum rcf can be up to 20,000~g, the individual models reach 60000xg; the centrifugal capacity can reach 3000ml.Toilet Cleaner
Toilet Cleaner,Toilet Bowl Cleaner,Toilet Cleaning,Toilet Cleaning Powder
Wuxi Keni Daily Cosmetics Co.,Ltd , http://www.kenicosmetics.com