Continuous cell culture

MammaBan. For mammalian proteins, mammalian cells offer the most natural host for expression. Problems of incorrect processing and post-translational modification are avoided using these cells. Mammalian cells are usually grown in continuous cell culture, reducing the variabiUty in results (see Cell CULTURE technology). Moderate-level production of native protein is possible. The procedure, however, is slow and very cosdy, and the level of protein expression is low. Thus large-scale production of proteins in mammalian cells is not practical. When low quantities of protein are sufficient, this system offers the several advantages described. 

There is an interior optimum. For this particular numerical example, it occurs when 40% of the reactor volume is in the initial CSTR and 60% is in the downstream PFR. The model reaction is chemically unrealistic but illustrates behavior that can arise with real reactions. An excellent process for the bulk polymerization of styrene consists of a CSTR followed by a tubular post-reactor. The model reaction also demonstrates a phenomenon known as washout which is important in continuous cell culture. If kt is too small, a steady-state reaction cannot be sustained even with initial spiking of component B. A continuous fermentation process will have a maximum flow rate beyond which the initial inoculum of cells will be washed out of the system. At lower flow rates, the cells reproduce fast enough to achieve and hold a steady state. 

Smith, M.A.L. et al.. Continuous cell culture and product recovery from wild Vaccinium pahalae germplasm, J. Plant Physiol, 150, 462, 1997. 

Okey, A.B., Bondy, G.P., Mason, M.E., Nebert. D.W., Forstergibson, C., MuncaN, j., and Dufresne, M.J. (1980). Tfemperature-dependent cytosol-to-nuclease translocation of the Ah receptor for 2,3,7,8-tetrachlorodi-benzo-p-dioxin in continuous cell culture lines, J. BioL Chem. 255,11415. 

Continuous cell culture (patented) [25] Cell-expansion apparatus (patented) [26] Production of a concentrated solution from biological substances (patented) [27]... 

Nicholson ML, Hampson BS, Pugh GG Ho CS (1991) Continuous cell culture. In Ho CS Wang DIC (eds) Animal Cell Bioreactors, pp. 269-303. Butterworth-Heinemann, Stoneham, MA. 

Ray NG, Tung AS, Hayman EG, Vournakis JN Runstadler PW Jr (1990) Continuous cell culture in fluidized bed reactors cultivation of hybridomas and recombinant CHO cells immobilised in collagen microspheres. Annals of the New York Academy of Sciences, Biochemical Engineering VI 589 443-457. 

Immortal cell culture See Continuous cell culture . 

It has been possible to cultivate in vitro normal diploid human cell strains from a variety of tissues, including all the soft organs, skin, membranes, bone marrow, and peripheral leukoc)rtes this is also possible for many primates, rodents, and others. The techniques for initiation and maintenance of continuous cell cultures will not be described here. The reader is referred to standard texts and research papers on tissue and cell culture. We must, however, consider several aspects of the biology of cultured mammalian cells that have direct bearing on the genetic, especially mutational, studies. 

Continuous cell culture A culture apparantly capable of an unlimited number of population doublings (often referred to as immortal). 

Most bioproducts of interest are retained inside cultured cells, which requires harvesting cells from support matrixes to extract the products. This makes continuous cell culture or reuse of cultured cells impossible and defies the whole idea of cell immobilization. 

Frank, U., Rabinowitz, C., and Rinkevich, B. (1994) In vitro establishment of continuous cell cultures and cell lines from ten colonial cnidarians. Mar. Bid., 120,491-499. 

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