Dextran as protectant against damage caused by sparging for hybridoma cells in a bubble column.

The effect of the addition of dextran as a protective polymer against sparging was examined with hybridoma suspension cells in a bubble column under standardized conditions. The protective effect of high concentrations of high molecular weight dextran showed a correlation with the bulk viscosity of the medium. A distinct protective effect occurs at viscosities greater than 20 x 10(-3) Pa s-1. In contrast, low molecular weight dextrans that cause a minor increase in viscosity, also provide no protection against sparging. There is no strict correlation between surface tension and the protective effect of dextran against sparging. Oxygen transfer is strongly reduced by high concentrations of high molecular weight dextran. Therefore, addition of dextran as protective polymer against sparging for large-scale production processes with animal cells in stirred reactors does not seem feasible.