This book captures, in the form of concise papers of limited length, the essence of the latest development in those fields of animal cell technology. We hope that it will become a useful resource of the most up to date information in Animal Cell Technology, at least until the next meeting in May 2003 in Spain. Elisabeth Lindner-Olsson Nathalie Chatzissavidou Elke Lullau Acknowledgements This meeting would not have been possible without the help of a large number of people, some of whom you will find mentioned below. In addition to the Organizing Committee and the Scientific Committee, Mrs Eva Ljung­ kvist and Mrs Ewa Engstrom of SKD Konferensservice have been most important to us. They have had to bear with us, scientists with specific demands for everything. Mrs Ewa Engstrom has also, together with Dr Bjorn Lundgren, organized the trade fare and the fund raising. Mr Henrik Levin at SKD has coordinated the distribution of all confirmation letters for oral presentations and posters as well as the coordination of the manuscripts for the proceedings. We would also like to thank Micael Worbin at TylOsand for local coordination. We have just had a stimulating, pleasant and enriching ESACT 2001 meeting. Your participation was a success and we feel privileged and honored that you decided to come to TylOsand.