Major centrifugation methods for bioanalysis

There are two major forms of centrifugation commonly encountered namely differential centrifugation and density gradient centrifugation. Furthermore, as indicated earlier, centrifugation can be used in both preparative and analytical modes, providing powerful tools for bioanalysis. 

During subcellular fractionation, various markers can be used as a quality control measure, giving an assessment of the quality of separation of individual fractions for example, DNA can be used as a marker for the step sedimenting nuclei, while the enzyme succinate dehydrogenase can be used as a marker for the step sedimenting mitochondria. Of course, to obtain a pure organelle fraction from differential centrifugation is virtually impossible. 

Grinding/homogenization to break up tissue and composite ceiis 

Homogenate (tissue/ceii preparation) -ready for centrifugation 

For zonal density gradient centrifugation there are a number of media that can be used, however the most common of these is sucrose whereas the most common medium for isopycnic density gradient centrifugation is caesium chloride (CSCI2). 

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