Antigen production for monoclonal antibody generation.

The quality of the target antigen is very important in order to generate a good antibody, in particular when binding to a conformational epitope is desired. The use of mammalian cells for recombinant protein expression provides an efficient machinery for the correct folding and posttranslational modification of proteins. In this chapter, we describe a process to rapidly generate semi-stable human cell lines secreting a recombinant protein of interest into the culture medium. Simple disposable bioreactors that can be used in any standard cell culture laboratory enable the production of recombinant protein in the multi-milligram range. The protein can be readily purified from the culture supernatant by immobilized metal affinity chromatography. In addition, by inserting a tag recognized by a co-expressed biotin ligase, the protein can be biotinylated during the secretion process. This greatly facilitates the immobilization of the protein for assay development or for antibody isolation using in vitro selection technologies.