Why a Second Edition? The Second Edition provides practical answers to the general question, "How can I obtain useful sequence information from my protein or peptide?" rather than the more specific question asked in the first edition, "How can I obtain the N-terminal sequence?" Important new methods include ways of dealing with blocked N termini, computer analysis of protein sequences, and the recent revolution in mass spectrometry. Key Features Highlights of the Second Edition: * Mass spectrophotometric characterization of proteins and peptides * N-terminal sequencing of proteins with blocked N termini * Internal amino acid sequence analysis after protease digestion in-gel and on-blot * Improved microscale peptide purification methods * Computer analysis of protein sequences * New protocols tested and refined through everyday use in authors' laboratories * Updated reference chapter covering all aspects of protein microsequencing