It is hard to think of a protein in eukaryotic cells that does not undergo some type of posttranslational modification. The covalent attachment of l- ids to proteins, protein lipidation, occurs for a few thousand proteins. Several functions for protein lipidation are known. Protein lipids may target proteins to specific cellular membranes, they may serve as molecular switches that allow cytosol-to-membrane transfer, they may direct protein-protein compl- ation, and they may stabilize protein structure. In cases such as the fatty a- lation of intracellular loops of transmembrane proteins, the funtions of the protein lipidations are not known. This volume-Protein Lipidation Protocols-provides detailed meth- ologies for the study of these processes. Since this is a rapidly growing field, many new experimental techniques have been developing over the past few years. All of the experimental techniques described in this volume have emerged during this time. The editor has made a special effort to include only those techniques that have not been previously described in a "hands-on" f- mat.