This volume includes 19 contributions to the 13th International Symposium on Analytical Ultracentrifugation which took place at the university of Osnabrück on March 6th and 7th, 2003. The contributions from leading scientists cover a broad spectrum of topics concerning: Technical Methods, Data Analysis, Innovations; Polymers, Colloids, Supramolecular Systems; Biological and Interaction Systems; Hydrodynamics and Modelling. Due to the increasing significance of Analytical Ultracentrifugation for both scientific and technical applications, this book will be an essential source of information with respect to recent developments and results related to this important analytical method.