This chapter provides guidance and procedures used for characterization of biotechnology-derived articles by peptide mapping. This chapter is harmonized with the corresponding chapter in JP and EP. Portions of the chapter that are not harmonized with the other two pharmacopeias are marked by the symbol ⧫. Other characterization tests, also harmonized, are shown in Biotechnology-Derived Articles—Amino Acid Analysis 〈1052〉,Capillary Electrophoresis 〈1053〉, Biotechnology-Derived Articles—Isoelectric Focusing 〈1054〉, Biotechnology-Derived Articles—Polyacrylamide Gel Electrophoresis 〈1056〉, and Biotechnology-Derived Articles—Total Protein Assay 〈1057〉.