Cell Culture Growth & Productivity Performance

Growth assay: CD CHO Medium is a protein-free, chemically defined medium designed for CHO applications (4) (Life Technologies). To evaluate the capability of the test medium to support cell growth, we utilized a dhfr+ CHO cell line (ATCCCRL-9096) generated using 1.2μM methotrexate (American Type Culture Collection). Cells were incubated in suspension culture at 37°C with starting concentration of 2x10⁵ cells per ml in T25 tissue culture flasks in 8% CO₂ for 3 serial passages. Cell counts were obtained electronically using a Model Z2 Coulter counter with viabilities determined by Trypan blue dye exclusion.