Cell fractionation

Cell fractionation is the process used to separate cellular components while preserving individual functions of each component.

Tissue is typically homogenized in a buffer solution that is isotonic to stop osmotic damage. Mechanisms for homogenization include grinding, mincing, chopping, pressure changes, osmotic shock, freeze-thawing, and ultra-sound. The samples are then kept cold to prevent enzymatic damage.

This step may not be necessary depending on the source of the cells. Animal tissue however is likely to yield connective tissue which must be removed. Commonly, filtration is achieved either by pouring through gauze or with a suction filter and the relevant grade ceramic filter.

Purification is achieved by differential centrifugation – the sequential increase in gravitational force results in the sequential separation of organelles according to their density.

Media for cell separation by density:

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