Principle

Principle

  • The living cell contains a number of subcellular particles.
  • Much of the knowledge of the functions and enzymic properties of these particles has been derived from a study of pure preparation of them.
  • Cell fractionaqtion procedures involve cell homogenisation followed by separation of different cellular components.
  • The fractionation of cells involves two distinct phases: disruption of the tissue or cells in a suitable medium and the subsequent separation of the subcellular particles, by differential centrifugation which exploits differences in their size and density.
  • This procedure results in rather crude subcellular fractions which are enriched with one particular component and are by no means pure.
  • These fractions are then purified by density gradient centrifugation.
  • The identity of the type of organelle isolated in a particular fraction is checked by microscopic examination and by looking for the presence of a compound or enzyme characteristics of it; the latter is known as marker.
Last modified: Saturday, 12 November 2011, 10:24 AM