This symposium is devoted to Biotechnology in Blood Transfusion; there are 22 experts discussing the state of the art in the application of monoclonal anti bodies, recombinant DNA technologies and heterologous expression systems to the improvement and sometimes replacement of blood products, charac terization of blood constituents, and the effect of these developments on blood transfusion procedures. Ten and maybe five years ago the title of a symposium such as this would have been Biosciences in blood transfusion, informing what basic developments in molecular biology, biochemistry and human physiology might pertain to blood transfusion in the distant future. That future is getting closer, and not only one is interested in basic developments in immunology, recognition and identification of viral and bacterial components and products, tissue and blood bloodgroup blood group typing, typing, but also in the potential application of these developments and their economic perspectives. That is what biotechnology is all alI about: basic science telIs tells us where and how we might look for new technologies, and the development of such tech nologies is only possible if there is a perspective for improvement in quality, safety, acceptance or performance to cost ratio.