BIOC23H3 Lecture Notes - Sedimentation Coefficient, Centrifugal Force
2 May 2012
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Lec 2: cell fractionation and centrifugation: cellular components and macromocs are temporally and spatially rearranged, cell fractionation: separate heterogenous cellular components into homogenous sets. Physical force: cells w/ cell walls. Freeze/thaw method protective reagent (10% glycerol/dmso) protects membrane so that cell will remain intact. French pressure = applied high pressure to cell: 2) filtration (opt) = remove unbroken cells/unwanted tissues, 3) purification = separate diff components by differential, 4) further protein purification (opt) based on specific protein centrifugation properties: Affinity: only do differential centrifugation if you want to purify some protein that"s trapped within organelle or membrane vesicles. So, for a given particle, it will move to the bottom at a constant speed. Particles w/ diff sedimentation coefficient will move w/ diff speeds: the sedimentation coefficient (s) and therefore the speed is dependent on: P = solution density f = friction ratio = particle shape. Particle will move from top of tube to the bottom when high centrifugation force applied.
