Filling a gap in the literature of biophysical methodology, this book explains the fundamentals in the theory and practice of AUC. It introduces the basic principles and technical setup of an AUC experiment and describes the optical systems used for detection. It explores the ultracentrifugation experiment from a macromolecular standpoint, offering a detailed physical picture of the sedimentation process and relevant macromolecular parameters. The authors present important practical aspects for conducting an experiment and cover instrument calibration and quality control experiments.