This edited book is written for students, postdocs and established investigators who want to enter the field or single-particle cryo-EM. This is a recently developed method to determine high-resolution structures of biological macromolecules. A major strength is the fact that cryo-EM does not require prior crystallization of protein complexes. Furthermore, it is especially well suited to deliver high-resolution structural information about multiple-conformational states. Authors of individual sections of this book have been recruited from among the most authoritative leaders in each topic. As a result, this book provides a comprehensive and authoritative coverage of key topics involving theory, data collection, data analysis and validation of results. The co-editors are well-recognized and highly respected leaders in the field of cryo-EM, active members of the Biophysical Society, and members of the US National Academy of Science Professor Glaeser (UC Berkeley) made major contributions to the initial development of cryo-Em technology, and he currently is active in the improvement of specimen preparation. Professor Nogales (UC Berkeley) has used cryo-EM throughout her scientific career, successfully applying this technique for the last three decades that defined structural characterization, Professor Chiu (Standford University) developed early experimental and computational methods towards 3D structure determination of biomolecules toward atomic resolution; contributed to the establishment of validation methods to assess cryo-EM structures Book jacket.