Over the past ten to fifteen years, animal cell biotechnology as a means of producing pure protein products (as opposed to vaccines) has advanced from being an essentially research laboratory-based technology to being a fully fledged player in the biopharmaceutical manufacturing industry. An increasing proportion of products of major clinical importance are produced in animal cells, essentially because accurate and authentic post-translational processing is necessary for the effective functioning of many diagnostic and therapeutic proteins.

This rapid growth to maturity has been made possible by rapid advances in the wide range of technical areas which need to be brought together to achieve safe and cost effective product generation in animal cells. This book has sought to identify these key areas of advancement, to review present progress and to highlight remaining obstacles. The following points represent the major landmarks in the development of animal cells as usable bioreactors and indicate where future research emphasis might be placed to further improve quality and productivity.

The altered regulatory stance to animal cells used as bioreactors

Probably the key event in the resurgence of animal cells as bioreactors for the production of pharmaceuticals was the radical evolution of regulatory attitudes which permitted the use of continuous cell lines as substrates for production. This was made possible by, on the one hand, advances in knowledge of the risks that products from animal cells might pose to patients and a rational assessments of these risks relative to the benefits, and on the other hand, by the development and acceptance of technologies able to reduce these risks to acceptable levels.