Suspension cultures, animal cell

Plaques may be obtained for animal viruses by using animal cell-culture systems as hosts. A monolayer of cultured animals cells is prepared on a plate or flat bottle and the virus suspension overlayed. Plaques are revealed by zones of destruction of the animal cells. 

Cells are grown either in suspension in a free or immobilized form 102), or by adherence to a solid surface 100). Materials used for promoting surface-dependent cell growth are glasses, metals, plastics, carbohydrate polymers etc. the media used contain substances such as blood plasma, amniotic fluids, tissue extracts, etc.103). Recent developments in animal cell culture are aimed at the improvement of strains and culture techniques, medium optimization, and scale-up. In contrast to plant cell culture, animal cell culture has already found its technical application. Large-scale... 

When animal cells are removed from the body, the cells can be maintained (or cultured) for prolonged periods, provided the cells are in an appropriate alternative environment. Environmental factors of importance for animal cell culture include the culture medium, substratum (or surface of the culture vessel), and temperature. The substratum (or surface) is a significant factor for those animal cells which grow attached to the surface of the culture container. A number of types of animal cells (such as lymphoid cells) grow in suspension. 

Animal cell cultures that are initiated from cells removed directly from the animal are called primary cultures (Figure 2). Primary cultures include both explant cultures (i.e., cultures initiated from small pieces of intact tissue), as well as cultures initiated from preparations of individual or dispersed cells (obtained from intact tissue by mechanical or proteolytic dismption). Nerve fiber explant cultures in blood plasma were among the earliest types of tissue cultures (Harrison, 1907). Cells grow out from such tissue explants and form a single layer of cells completely filling the tissue culture vessel surface. Such cell cultures are called confluent monolayers. Confluent monolayers can then be treated with trypsin, so as to remove the individual cells from the culture vessel surface. The resulting cell suspension is then transferred into other culture containers, so that more viable monolayer... 

Varley, J. and Birch, J. 1999. Reactor design for large scale suspension animal cell culture. Cytotechnology 29(3), 177-205. 

The presence of two types of cells in the population, lymphocyte-like and epithelium-like, is the characteristic feature of hybrid cultures of cells with lymphocytes of domestic animals. Correlation of these two types of cells is different, however by the method of the directed selection it is possible to increase the population of lymphocyte-like cells to 60-80% and more, because even at stationary cultivation lymphocyte-like cells go away into suspension ... 

Varley, J Birch, J. (1999). Reactor design for large scale suspension animal cell culture. Cytotechnology 29(3), 177-205. Wright, G. et al. (1991). High level expression of active human -antitrypsin in the milk of transgenic sheep. Bwj Technology 9, 830-834. 

Animal cells may be anchorage-dependent. Cells that depend on a solid substratum for growth are named adherent cells. These cells normally proliferate in monolayers and show contact inhibition, with the maximum cell yield generally limited by the available surface of the culture vessel. The yield of cells in suspension is not dependent on a solid substratum. 

Table 2.1 Adherent and suspension cell lines commonly employed in animal cell culture...

For suspension cultures, the concentration of calcium and magnesium should be kept low to prevent cell aggregation and adhesion. Other metals, such as iron, manganese, selenium, vanadium, zinc, copper, and molybdenum, are usually added to the culture medium, but at reduced concentrations, and mainly if the medium is not supplemented with animal serum. 

Kioukia N, Nienow AW, Emery AN, Al-Rubeai M (1992), The impact of fluid dynamics on the biological performance of free suspension animal cell culture further studies, Trans. I. Chem. Eng. 70 143-148. 

Etcheverrigaray M, Amadeo G, Didier C, Pereira Bacci D, Cavatorta FA, Kratje R (2005), Physicochemical estimation of rhEPO potency produced in suspension culture, In Godia F, Fussenegger M (Eds), Animal Cell Technology Meets Genomics, Springer, Dordrecht, pp. 727-729. 

---