Hands-on experts describe in step-by-step detail the key methodologies of contemporary peptide synthesis and illustrate their numerous applications. The techniques presented include protocols for chemical ligation, the synthesis of cyclic and phosphotyrosine-containing peptides, lipoamino acid- and sugar-conjugated peptides, and peptide purification and analyses. Additional chapters detail methodologies and instrumentation for high-throughput peptide synthesis, many different applications of peptides as novel research tools and biological probes, and the design and application of fluorescent substrate-based peptides that can be used to determine the selectivity and activity of peptidases. A practical guide to the identification of proteins using mass spectrometric analyses of peptide mixtures is also included.