Generation of high-recombinant- protein-producing Chinese hamster ovary (CHO) cells.

The purpose of this chapter is to propose a practical procedure for the generation and selection of Chinese hamster ovary cells producing high levels of recombinant protein by combining in vitro and in vivo amplification of the foreign gene. A detailed description of the expression and amplification plasmids utilized for the in vitro generation of long DNA concatenamers, as well as the cell transfection and selection protocols are given. The procedure required for in vivo gene amplification using the dihydrofolate reductase/methotrexate system is also described.