In recent years researchers have turned to transient gene expression (TGE) as an alternative to CHO stable cell-line production for early-stage antibody development.
There are variety of CHO cell transient transfection platforms, including engineered CHO cells, unique expression constructs, specialized reagents, and proprietary technologies. These systems as well as highly optimized protocols for lipids and polyethylenimine (PEI) have varying levels of reproducibility, scalability, and cost effectiveness, and in general produce antibody titers from 10 to 100 mg/L for a typical IgG.
These systems generally have even lower expression levels for difficult-to-express molecules such as bi-specific antibodies.
A flow electroporation technology available from MaxCyte has been shown to scale from milligram to multigram quantities of CHO antibodies without requiring specific expression constructs, engineered CHO cell lines, specialized reagents, or customized culture media. Secreted antibody titers are routinely greater than 400 mg/L and can exceed 1 g/L.
MaxCyte offers two benchtop systems: the MaxCyte STX® Scalable Transfection System and the MaxCyte VLX® Large Scale Transfection System. This technology has the capacity to transfect from 5E5 cells in seconds up to 2E11 cells in less than 30 minutes and has been used to transfect a variety of adherent and suspension CHO cell lines.