Mammalian cells

Transient gene expression in HEK293 cells has been widely used in recent years since it can produce substantial amounts of soluble and active eukaryotic proteins in a reasonable time. The development of transfection protocols that use the cationic polymer polyethylenimine (PEI) to carry the plasmid DNA into the cells, has facilitated the of transient gene expression for large-scale protein production. HEK293 cells are one of the most frequently used cell lines for this purpose since they are easy to maintain, and high transfection efficiencies are achieved using the PEI carrier. The pHLsec expression vector is used for either intracellular expression or for proteins to be secreted into the medium.