This edited volume discusses the identification, discovery, characterization, structure determination and modeling of multicomponent macromolecular complexes, and as such, it fully complements the first volume (ISBN 978-3-319-27214-6), which targeted methods of recombinant production of protein complexes. This book is divided in 8 sections offering a selection of technologies widely used in the characterization of protein and protein-nucleic acid complexes for different purposes and at different scales. From native electrophoresis methods, that are accessible to any reasonably well-equipped laboratory, to the sophisticated setup required for structure determination by cryo-electron microscopy or X-ray crystallography, this book contains a wide variety of clearly explained analytic and preparative approaches, connected with the production techniques developed on the previous volume. The readers will find an integral connection between this book and the first volume, which ensures a comprehensive and updated discussion of the main topics of the discipline. Taken together, these volumes constitute a cohesive and authoritative source of the research on multicomponent macromolecular complexes. In here, we focus on characterization of protein complexes in the broadest sense, which is not typically covered in other sources. Moreover, all chapters are carefully written by world renowned scientists and active researchers, making this volume ideal, not only as a reference source, but also as a companion book for the daily laboratory work. This book is aimed for a wide range of scientists, from science students to experienced researchers, working on protein and protein-nucleic acid complexes, who need a thorough understanding of protein production and complex characterization.