Mammalian cells, density gradient

Mammalian Cells, Density Gradient Electrophoresis of (Tulp). 30 141... 

Use of alkaline sucrose gradients Another but less sensitive means of detecting SSBs in mammalian cell DNA is the use of alkaline sucrose density gradients (see Meneghini, 1976). As was the case in the use of the elution methods (Section 8.2.1.2) an essential preliminary step is the extensive labelling of cellular DNA by incubation of cell cultures with [3H]thymidine (Adams, this series, 1980). These labelled cell cultures can then be variously exposed to potential DNA-damaging agents. 

Tutp, Abraham, Density Gradient Elearophoresis of Mammalian Cells. 30... 

The most common materials used to generate density gradients are sucrose, Ficoll, and Cs salts. Sucrose solutions can be as concentrated as 65% w/w, with a maximum density of 1.32 g/cm3 at 4 °C however, concentrated solutions of sucrose have high osmotic strength and viscosity. Ficoll is a brand name for a synthetic polysaccharide with an average MW of 400,000 and a maximum density in aqueous solution of 1.23. It is very useful to separate osmotically sensitive particles, like mammalian cells. 

Cells in aqueous suspension preferably are separated by physical methods under well-defined experimental conditions rather than by chemical modification that influences cellular viability or initiates cellular processes. Moderate physical forces and short separation time gready contribute to cellular integrity. In this chapter, the application of density gradient electrophoresis to the separation of mammalian cells is described. This process may be defined as the differential zonal movement of cellular particles of anionic character suspended in a stabilized liquid column under the influence of an external electrical field so that collection of differentially moved zones is feasible. 

DENSITY GRADIENT ELECTROPHORESIS OF MAMMALIAN CELLS 159 D. THE LKB COLUMN... 

As prototypic mammalian cells, erythrocytes have been used almost solely to test the resolving power of density gradient electrophoresis columns. To perform a large number of tests, erythrocytes may be fixed by dilute aldehyde solutions (Vassar et al., 1972) to obtain particles that are chemi-... 

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