Centrifuges

• Centrifuge is an equipment driven by electric motor that puts an object in rotation around fixed axis
• Centrifuge used for separating particles from a solution according to their size, shape, density, viscosity of the medium and rotor speed.
• Principle :

  1. When a body is rotated in a circular movement at high speed, it creates a centrifugal force.
  2. At the centrifugation, the centrifugal force of spinning pushes the solid particles of higher density outwards, which pack in the narrow bottom of centrifuge tube & form a pellet.
  3. The packing of a solid particle facilitates the separation of the supernatant which is then decanted out.
• Types of rotor:

  1. Swinging bucket - horizontal, easy to withdraw supernatant
  2. Fixed-angle - slanted, hold more centrifuge tubes
• Speed :

  1. RPM (resolution per minute)
  2. RCF (relative centrifugal force)