Introduction. Strategies for Obtaining Partial Amino Acid Sequence Data from Small Quantities (5nmol) of Pure of Partially Purified Protein. Enzymatic Digestion of Proteins and HPLC Peptide Isolation. Purification of Proteins and Peptides By SDS-PAGE. Internal Amino Acid Sequence Analysis of Proteins After in Situ Protease Digestion on Nitrocellulose. Mass Spectrometric Strategies for the Structural Characterization of Proteins. Appendix. References. General Reference Books on Protein Microsequencing Methodologies.