METHODS VECTORS PLASMIDS AND METHODS FOR INCREASING EXPRESSION OF RECOMBINANT POLYPEPTIDES

摘要

The present invention provides novel methods and materials for increasing th e expression of recombinant polypeptides. Methods and materials of the inventi on allow increased expression of transcription units that include recombinant D NA sequences which encode polypeptides of interest. The present invention provides expression vectors which contain multiple copies of a transcription unit encoding a polypeptide of interest separated by at least one selective marker gene and methods for sequentially transforming or trasnfecting host cells with expression vectors to increase transcription unit dosage and expression.