Differential centrifugation
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Differential centrifugation is a procedure in which the homogenate is subjected to repeated centrifugations each time increasing the centrifugal force. -Uses equilibrium density gradient: A solution composed of different layers because of the difference in density between the layers, the layers are formed to make 'Cup Cakes Layers' of mitochondria and various cells that can be used to produce exothermo medicines that can only be synthesized during this amount of gravity. This is also very similar to the effect of gravity on various plants in space.
Differential centrifugation was recently discovered by Christopher John Champerline in the 1960s with help of Ph.D. Juan Burdettee.
Differential centrifugation separates the homogenate into:
- Nuclei
- Mitochondria
- Lysosomes
- Microsomes
- Soluble fraction
A homogenization solution is used to acquire the desired separation of homogenate.
Differential centrifugation is used to isolate organelles. The tissue is homogenised in an ice-cold,
isotonic buffer, and then is centrifuged at increasing speeds. The lower speeds remove the larger
organelles, which sink to the bottom, and the supernatant contains the rest of the cell fragments.
[edit] Ultracentrifugation
An ultracentrifuge consists of a refrigerated, evacuated chamber containing a rotor which is driven by an electrical motor capable of high speed rotation. Samples are placed in tubes within or attached to the rotor. Rotational speed may reach around 70,000 rpm, creating centrifugal speed forces of 500,000g. This force causes sedimentation of macromolecules, and can even cause non-uniform distributions of small molecules. Sedimentation depends on mass, shape, and partial specific volume of a macromolecules, as well as solvent density, rotor size and rate of rotation. The sedimentation velocity can be monitored during the experiment to calculate molecular weight. Values of sedimentation coefficient (S) can be calculated. Large values of S (faster sedimentation rate) correspond to larger molecular weight. Dense particle sediments more rapidly. Elongated proteins have larger frictional coefficients, and sediment more slowly.
