Centrifugation Case Study

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Centrifugation is used to separate different classes of particles in a heterogeneous mixture by rapid centrifugation at increase relative centrifugal force (RCF) in terms of gravitational units (x g). After each centrifugation, heterogeneous mixture released subcellular organelles such as nuclei, mitochondria as sediment. Sediment material is large, heavy organelles such as nuclei or plasma membrane that called pellet. A homogenates is subjected to low speed centrifugation. Also, other material remains in the fluid called the supernatant fraction. The pellet is separated from sediment carefully. This process is repeated several times. In each centrifugation is carried out at raptly higher speeds until whole series of pellets are taken out of solution (Sheeler, 1981). …show more content…

At each speed, the resulting force causes a fraction of the cell components to settle to the bottom of the tube, forming a pellet. At lower speeds, the pellet consists of large components and higher speeds yield a pellet with smaller (Reece. et. al., 2014) Bivalve molluse (oyster) can be homogenized by physical and chemical method. Physical to use for oyster are chopping, and grinding. Potential sources of physical damage include the denaturation of proteins, RNA and DNA upon exposure to a different temperature and also damage caused by the homogenization technique. Chemical methods are osmatic chemical lysis, sonication or freeze-thaw cycles. Potential sources of chemical damage include: the degradation of proteins, RNA and DNA by proteases, RNAse and DNAse respectively that are released from the tissue when it is homogenized. Selective excision of oyster tissue, the stomach of oyster was avoided because stomach has a high amount of enzymes such as pepsin and trypsin that degrade

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