The international symposia on blood transfusion in Groningen have taken place without interruption since 1976. Each year Dr. Smit-Sibinga and his team have not only organized a meeting on timely topics in blood transfusion, but also succeeded in attracting prominent chairmen and speakers. The subject of the 24th Symposium was Molecular Biology in Blood Transfusion and it was chaired by Dr. Harvey G. Klein, National Institutes of Health, USA. In this book of proceedings an extraordinary range of subjects is covered, including diagnostic aspects, virology, quality control, cell and protein processing as well as a section on new horizons in clinical medicine.