title: Transient transfection of CHO-K1-S using serum-free medium in suspension: a rapid mammalian protein expression system.
abstract: With the recent completion of the human genome sequencing project, scientists now face the daunting challenge of deciphering the function of these newly found genes quickly and efficiently. For biotechnology, it is equally important to identify the therapeutically relevant genes as quickly as possible. Mammalian expression systems provide many advantages to aid in this task. Mammalian cell lines have the capacity for proper post-translational modifications, including proper protein folding and glycosylation. In response to these needs, a CHO-K1 cell line that grows in suspension and in serum-free media was initially established and designated CHO-K1-S. An antibody gene of interest was chosen as the target for optimization rather than a reporter gene system. A comparison of various lipid transfection reagents was made using recombinant protein expression as the endpoint readout. Various other parameters including lipid:DNA ratios, cell density, and transfections in shaker versus spinner flasks were tested using the CHO-K1-S cell line. As a result, a rapid and reliable transient transfection protocol was developed. Using this procedure, we have produced milligram/per liter quantities of bioactive recombinant proteins from several genes of interest.
authors.affiliation: Cell Sciences Department, Berlex Biosciences, Richmond, CA 94804, USA.
authors.forename: Mary P
authors.initials: MP
authors.lastname: Rosser
authors.forename: Wei
authors.initials: W
authors.lastname: Xia
authors.forename: Steven
authors.initials: S
authors.lastname: Hartsell
authors.forename: Michael
authors.initials: M
authors.lastname: McCaman
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.forename: Soujuan
authors.initials: S
authors.lastname: Wang
authors.forename: Susan
authors.initials: S
authors.lastname: Harvey
authors.forename: Peter
authors.initials: P
authors.lastname: Bringmann
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Cobb
mesh_terms: D000818:Animals; D016466:CHO Cells; D003001:Cloning, Molecular / Q000379:methods*; D006224:Cricetinae; D003412:Cricetulus; D016895:Culture Media, Serum-Free; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics; D007202:Indicators and Reagents; D051379:Mice; D011994:Recombinant Proteins / Q000235:genetics*; D014162:Transfection / Q000295:instrumentation / Q000379:methods*
chemical_list: D016895:Culture Media, Serum-Free; D007141:Immunoglobulin Fc Fragments; D007202:Indicators and Reagents; D011994:Recombinant Proteins