Figure 1.
Increased antibody titers upon culturing at high cell densities postelectroporation. A total of 1 × 1010 CHO-S cells were electroporated with an antibody expression plasmid (1 µg DNA/1 × 106 cells). Postelectroporation cells were inoculated into 2 shake flasks at high and medium viable cell densities (VCDs: 6 × 106 or 1 × 107 cells/mL, respectively) and cultured with daily feeding using unsupplemented CD OptiCHO medium. Sodium butyrate (1 mM) was added to both cultures and the temperature lowered to 32 °C 24 h postelectroporation. (A) VCD and (B) antibody titers were measured through day 15 postelectroporation.