Serum-free Systems

Cell and Tissue Culture Laboratory Procedures in Biotechnology, edited by A. Doyle and J.B. Griffiths. 1998 John Wiley Sons Ltd. 

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Andersen et al. (1996) and Andersen (1995) have studied the effect of temperature on the recombinant protein production using a baulovinis/insect cell expression system. In Tables 17.15, 17.16, 17.17, 17.18 and 17.19 we reproduce the growth data obtained in spinner flasks (batch cultures) using Bombyx mori (Bm5) cells adapted to serum-free media (Ex-Cell 400). The working volume was 125 ml and samples were taken twice daily. The cultures were carried out at six different incubation temperatures (22, 26,28, 30 and 32 TT). 

HyClone is a supplier of cell culture and bioprocessing systems, which also offers customized work to configure particular applications. Services address activities, research, and production. Business is centered on culturing media, and consequently support is offer for the development of a given formulation. HyClone supplies FBS and other sera for cell culture, serum-free and protein-free media, etc. 

Tseng SC, Kruse FE, Merritt J, Li DQ. Comparison between serum-free and fibroblast-cocultured single-cell clonal culture systems Evidence showing that epithelial anti-apoptotic activity is present in 3T3 fibroblast-conditioned media. Curr Eye Res 15 973-984 (1996). 

Barnes DW, Sirbasku DA, Sato GH (1984b), Methods for Serum-free Culture of Cells of the Endocrine Systems, Alan R Liss, New York, p. 255. 

Despite being more critical for intracellular products, protease action may also occur in extracellular media. For example, in the expression of a baculovirus vector, which is a lytic system, proteases are often expressed and secreted during recombinant protein production, and the problem may assume a critical level. A similar problem occurs in serum-free culture systems. The absence of proteins such as albumin and macroglobulin reduces the protection against proteolysis. In these cases, addition of an antiproteolytic agent to the culture medium is recommended. 

Moro AM, Rodrigues MTA, Gouveia MN, Silvestri MLZ, Kalil JE, Raw I (1994), Multi-parametric analyses of hybridoma growth on glass cylinders in a packed-bed bioreactor system with internal aeration. Serum-supplemented and serum-free media comparison for MAb production, J. Immunol. Methods 176 67-77. 

Boisseau, A.M. Donatien, P. Surleve-Bazeille, J.E. Amedee, J. Harmand, M.F. Bezian J.H. Maleville, J. Taieb, A., Production of epidermal sheets in a serum free culture system a further appraisal of the role of extracellular calcium. J. Dermatol. Sci. 3, 111-120, 1992. 

The aim of most technologies is to generate a population of cells each of which secretes a desired product into the medium. For this to occur the cells do not need to be actively dividing and, in fact, this is sometimes counterproductive. Cells can remain viable at high cell densities using perfusion systems (Chapter 3) and the product purified from the spent medium (Spier, 1988). Furthermore, the simpler the growth medium (i.e. the fewer protein factors required) then the easier is the downstream processing and this is one reason for the development of serum-free media especially for the culture of hybridoma cells used for monoclonal antibody production ( 5.8). 

The role of ferredoxin in reactions of photosynthetic bacteria is summarized in Fig. 11. Reactions which should now be possible to show, but so far have not been observed in cell-free systems, are the fcrredoxin-dependent photoproduction of hydrogen gas and photoreduction of pyridine nucleotide. Hood (56) reported a two-fold stimulation by ferredoxin in the photoreduction of DPN by chlorophyll-containing particles from Chromatium. Hood s results were inconsistent and Hinkson (54) found that the ferredoxin requirement is not specific and may be satisfied by serum albumin. In addition, there is still no evidence for a role of ferredoxin in photophosphorylation by photosynthetic bacteria, similar to that in chloroplasts. 

A1 determination in serum Chromatographic system Stainless-steel free chromatographic system cleaning column 1.5 mM DFO, 12 h [90, 91]... 

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