Quantitative measurement of cell-bubble attachment in bubble columns using foam flotation techniques

Abstract

A simple and convenient system for quantitatively measuring the number of adsorbed animal cells per unit of bubble surface area (Γ, unit: cells/cm2) was developed. The system was successfully applied to recombinant Chinese hamster ovary (r-CHO) suspension cultures to investigate the dynamic cell-bubble attachment in a bubble column. In serum-free medium, Γ values increased with bubble rising height (H) and cell concentration (C) and then became constant (about 1750 cells/cm2) when H and C were sufficiently high. In medium containing protective additives, the trends of Γ values with H were similar to that in serum-free medium. Compared with serum-free medium, polyvinyl-pyrrolidone (PVP) increased the Γ values to 1941 cell/cm2 whereas other tested additives decreased the values of Γ in some different degree.