PROTEIN PROdUCTION in mammalian cells
Icosagen Cell Factory has established a mammalian protein production system, where the gene of interest is expressed from a plasmid that can stably replicate and maintain itself in mammalian cells. The method enables to perfom quick and efficient:
• production of recombinant proteins and antibodies in quantities up to 1.0 g/L for early stage and preclinical research and for development of biologics
• expression of virus-like particles (VLPs) for vaccine development
This new protein expression system is called QMCF Technology and consists of specially designed vectors and modified mammalian cells, which are based on CHO or HEK293 cells. Using QMCF Technology a cDNA of a target molecule is cloned into QMCF expression vector and transfected by electroporation into QMCF cells, which are grown in serum-free suspension. A special mechanism ensures high copy number of QMCF plasmids and succesful propagation into dividing daughter cells. Compared to transient protein production, where the production lasts only for few days, QMCF technology allows to extend the protein production cycle to 2-3 weeks. Thus the protein production yields achieved by our system exceed drastically yields of transient expression. Freezing and thawing of transfected QMCF cells allow generation of cell banks and makes further up‐scale quick and cost‐effective.
Protein production process includes three phases starting with small initial transfection volumes and scaling-up final amount to several liters during production phase. High cell densities and high expression levels allow protein production from several milligrams to gram amounts within 3 weeks. Productivities of single sub-unit proteins vary up to 1g/L, in case of monoclonal antibodies 50-200 mg/l.
An example of the scale-up process of mammalian protein production from single electroporation using QMCF Technology in small scale amount:
