Zitzmann, J., Schreiber, C., Eichmann, J., Bilz, R.O., Salzig, D., Weidner, T., Czermak, P. (2018). Single-cell cloning enables the selection of more productive Drosophila melanogaster S2 cells for recombinant protein expression.  Biotechnol. Rep. (Amst) 19(): e00272.

FBrf0239414

Research paper

The generation of monoclonal cell lines is an important early process development step for recombinant protein production. Although single-cell cloning is an established method in mammalian cell lines, straightforward protocols are not yet available for insect cells. We describe a new method for the generation of monoclonal insect cells without using fetal bovine serum and/or feeder cells pretreated by irradiation or exposure to mitomycin. Highly productive clones of Drosophila melanogaster S2 cells were prepared in a two-step procedure, comprising the establishment of a polyclonal population and subsequent single cell isolation by limiting dilution. Necessary growth factors were provided by co-cultivation of single transformants with untransfected feeder cells, which were later removed by antibiotic selection. Enhanced expression of EGFP and two target peptides was confirmed by flow cytometry and dot/western blotting. Highly productive clones were stable, showed a uniform expression profile and typically a sixfold to tenfold increase in cell-specific productivity.

PMC6037645 (PMC) (EuropePMC)