This book is a record of the proceedings of a NATO Advanced Study Institute on "Transfer of Cell Constituents into Eukaryotic Cells" held September 2-14, 1979, at Sintra-Estoril, Portugal. Transfer of cell constituents into living cells can be brought about by a variety of ways, namely by microinjection with micropi- pettes (small somatic cells, oocytes and plant cells), by microin- jection using fusion methods (red cell mediated microinjection, li- posome mediated transfer, transfer of membrane components, cell hy- bridization and fusion of cell fragments)and by means of uptake (DNA and chromosome gene transfer). Prompted by the development~ in this exciting and expanding field of cell biology it seemed timely to meet to review the exist- ing knowledge and to speculate on future research applications. The lectures published here reflect the diversity of research currently underway using these techniques. The final outcome of the meeting was positive as it promoted collaboration between laboratories and, most important, created strong scientific and social links between individuals. We wish to express our appreciation to Dr. Maria C. Lechner and Mrs. Helena Gata for providing valuable advice and help through the initial planning stages of this meeting. Finally, we are indebted to Ms. Lisbeth Heilesen for her outstanding organization and admi- v vi PREFACE stration of the meeting and for typing all the manuscripts of this book. The meeting was held under the sponsorship of NATO with partial support from the Gulbenkian Foundation.