Cell Fractionation

• Cold Solutions to reduce enzyme activity, reducing damage
• Isotonic Solutions create same water potential to prevent osmosis
• Buffered Solutions prevent damage to organelles via pH
• Homogenisation is the process of breaking cells open to release contents
• Homogenisation occurs using a blender/homogeniser in cold, isotonic, buffered solutions producing a homogenate
• Filtration is the seperation of filtrate and debris
• Filtration occurs using a gauze which removes large debris
• Ultracentrifugation is the process of seperating materials by spinning at fast rates
• Ultracentrifugation use centrifuges to spin at variable speeds using centrifugal force to create pellets of heaviest cells, removing the supernatant and spinning again for lighter cells
• Differential Centrifugation (Heaviest to Lightest):

  • Nuclei
  • Chloroplasts
  • Mitochondria
  • Lysosomes
  • Endoplasmic Reticulum
  • Ribosomes