Although our understanding of the structure and activities of the cell nucleus and of the nanomachines which it contains is increasing rapidly, much remains to be learned. The application and continuing development of the new, powerful biochemical and biophysical methodologies described here are essential in this quest. In The Nucleus, researchers from more than forty leading international laboratories describe state-of-the-art methods for isolating nuclei and their components and for studying their structure and activities, including some pathology-associated features. Volume I: Nuclei and Subnuclear Structures presents an overview of features of the intranuclear environment, followed by the most recent procedures for isolating nuclei from a wide range of cell types including muscle cells, yeast, oocytes, cells with polytene nuclei, Arabidopsis, trypanosomes, and dinoflagellates. The latest methods are described for isolating and working with nucleoli, constitutive heterochromatin, pathology-associated inclusions, and chromatin and for examining glycosylation, sumoylation, and ADP-ribosylation of nuclear proteins. Written in the highly successful Methods in Molecular Biologya series format, chapters contain lists of necessary materials and reagents, readily reproducible protocols, and tips for troubleshooting and avoiding known pitfalls. The Nucleus, Volume I: Nuclei and Subnuclear Structures is an essential reference for scientists who are working on our rapidly growing understanding of the cell nucleus and its activities.