Abstract
Considerable increases in productivity have been achieved in biopharmaceutical production processes over the last two decades. Much of this has been a result of improvements in media formulation and process development. Though advances have been made in cell line development, there remains considerable opportunity for improvement in this area. The wealth of transcriptional and proteomic data being generated currently hold the promise of specific molecular interventions to improve the performance of production cell lines in the bioreactor. Achieving this-particularly for multi-gene modification-will require specific, targeted and controlled genetic manipulation of these cells. This review considers some of the current and potential future techniques that might be employed to realise this goal.