Fractionation is the process of breaking the cells. Firstly, the tissue is added to a solution which is ice cold, with the same water potential as the cells, and with the same PH as the cells. This has the purpose of preserving the cells so they do not rot. This solution is then homogenized, this is essentially blending the solution so the cells break open. There are four possible procedures for this, high frequency sound waves, a mild detergent, forcing cells through a small hole with high pressure, or a rotating plunger. This creates a homogenate which contains intact membrane bound organelles, as well as everything from the cytoplasm.
The Ribosomes now need to be separated out of the homogenate. The homogenate is placed into test tubes and into an ultracentrifuge. The ultracentrifuge is a refrigerated armoured box, containing a fixed-angle rotor which spins the test tubes at high speeds (see Fig.). The high speeds change the gravitational force exerted on the …show more content…
Ribosomes are too small to be seen with a light microscope, which can only magnify up to X2000 and can only resolve objects more than 200nm apart. The Scanning Electron Microscope (SEM) works by bouncing electrons of the surface of the specimen showing a 3D image on a computer screen. SEM can magnify up to X5000 and can resolve specimens 1nm apart. With this microscope the ribosomes could be seen and would show the shape, however the inside of the ribosome could not be seen. In contrast, the Transmission Electron Microscope (TEM) transmits the electrons through a very thin sample which would show what happens inside a ribosome. The TEM can magnify up to X750000 and resolve to 1nm. The TEM would be the best microscope to use to see the ribosomes but either the TEM or SEM could be