Over the past thirty years, many elegant genetic and biochemical approaches have been combined in order to advance the study of protein secretion and the necessary navigation through cell membranes, yet, despite this progress, less than two hundred membrane protein structures are known, nowhere near the complete inventory that the discovered protein export systems suggest. In Protein Secretion: Methods and Protocols , leading experts in the field provide robust, well-established protocols to elucidate the multiplicity of tools that have been developed to study protein sorting, membrane targeting, transmembrane crossing, and secretion across multiple membranes. With examples involving both prokaryotic and eukaryotic organisms, the volume covers subjects