The development and use of the analytical ultracentrifuge for studying the solution behavior of biomacromolecules goes back to the early pioneering efforts of Svedberg and his coworkers in the 1920s and 1930s. From this early period of time up until the 1970s analytical ultracentrifugation (AUC) played an important role in formulating our knowledge of the biophysical properties of biopolymers. Hence our early basic understanding of biomacromolecular structure and molecular biology is significantly indebted to this important analytical instrument. Nevertheless, with the development of size-exclusion chromatography, SDS-PAGE, and soft ionization mass spectroscopy techniques, along with major shifts in research in the biological and biomedical sciences during the following decades the role of AUC diminished to the point where it virtually disappeared as a form of macromolecular analysis. However, developments in electronics and computer technology (which has brought low cost computer power to the scientist's desktop) along with the renewed interests in understanding protein-protein interactions, and the realization of the need to have alternate analytical techniques to characterize the homogeneity and aggregation present in biopharmaceuticals has lead to the modernization and renewed interest in the analytical ultracentrifuge. Hence the subject of this presentation will focus on how AUC can be integrated into today's biopharmaceutical development process to help accelerate the successful discovery and development of new biopharmaceutical drug products.