Factors affecting yield and survival of cells when suspensions are subjected to centrifugation
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The goals of the centrifugation of cell suspensions are to obtain the maximum yield of cells with minimum adverse effects of centrifugation. In the case of mechanically sensitive cells such as mouse sperm, the two goals are somewhat contradictory in thatg-forces sufficient to achieve high yields are damaging, andg-forces that yield high viability produce low yields. This paper mathematically analyzes the factors contributing to each goal. The total yield of pelleted cells is determined by the sedimentation rate governed by Stokes’ Law, and depends on the relative centrifugal force, centrifugation time, size and shape of the cells, density of the cells and medium, viscosity of the medium, and the length of the column of suspension. Because in the situation analyzed the column is short relative to the rotor radius, the analysis considers the centrifugal field to be quasi-homogeneous. The assumption is that cells are not damaged during sedimentation, but that they become injured at an exponential rate once they are pelleted, a rate that will depend on the specific cell type. The behavior is modeled by the solution of coupled differential equations. The predictions of the analysis are in good agreement with experimental data on the centrifugation of mouse sperm.
Index EntriesMechanical sensitivity damage recovery sedimentation
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- 2.Mortimer, D. (1994)Practical Laboratory Andrology. Oxford University Press, New York, NY.Google Scholar
- 7.Tanford, C. (1961) Frictional coefficient of solid spheres and ellipsoids, inPhysical Chemistry of Macromolecules, Wiley & Sons Inc., New York, NY, pp. 326–328.Google Scholar
- 8.Miller, R. G. and Phillips, K. J. (1963) Separation of cells by velocity sedimentation.J. Cell Physiol. 73, 190–202.Google Scholar
- 9.Happel, J. and Brenner, H. (1965) The setting of orthothropic bodies, inLow Reionolds Numbers Hydrodynamics, Prentice Hall, Englewood Cliffs, NJ, pp. 220–223.Google Scholar