Dense cell-suspensions

The cells are grown and infected in suspension culture. To synchronize the infection a dense cell suspension is mixed with the virus inoculum, kept for one hour in an ice bath and then diluted ten-fold with warm medium and incubated for 7 5 h at 57 C. 

Intracellular products can be present either as folded, soluble proteins or as dense masses of unfolded protein (inclusion bodies). For these products, it is first necessary to concentrate the cell suspension before effecting release of the product. Filtration can result in a suspension of cells that can be of any desired concentration up to 15 to 17 percent and that can be diafiltered into the desired buffer system. In contrast, the cell slurry that results from centrifugation will be that of... 

Microscopic counts The nnmber of cells in a cnltnre can be connted under a microscope using a hemocytometer, which has counting chambers etched on the surface of a glass slide. A sample of cell suspension is allowed to flow under the cover slip and to All the counting chambers. Dense suspensions need to be diluted. 

The stirring effect was eliminated and the bacteria maintained in a constant and well defined environment in a measuring chamber with an immobilized layer of cells as depicted in Fig.l. A thin layer (down to 0.5 mm) of a dense bacterial suspension is separated by a dialysis... 

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