Book excerpt: Cryo-EM Part A: Sample Preparation and Data Collection is dedicated to a description of the instruments, samples, protocols, and analyses that belong to cryo-EM. It emphasizes the relatedness of the ideas, instrumentation, and methods underlying all cryo-EM approaches, which allow practitioners to easily move between them. Within each section, the articles are ordered according to the most common symmetry of the sample to which their methods are applied. - Includes time-tested core methods and new innovations applicable to any researcher - Methods included are useful to both established researchers and newcomers to the field - Relevant background and reference information given for procedures can be used as a guide