In the decade since publication of the first edition of Crystallographic Methods and Protocols the field has seen several major developments that have both accelerated the pace of structure determination and made crystallography accessible to a broader range of investigators. Volume I, Preparation and Crystallization of Macromolecules is dedicated to the crystallization and ways to increase the odds of obtaining crystals in macromolecules, while Volume 2, Structure Determination, covers both computational methods for characterizing crystals and solving structures.