This chapter provides guidance and procedures used for characterization of biotechnology-derived articles. This chapter is harmonized with the corresponding chapter in JP and EP. Other characterization tests, also harmonized, are provided in Biotechnology-Derived Articles—Amino Acid Analysis 〈1052〉, Capillary Electrophoresis 〈1053〉, Biotechnology-Derived Articles—Isoelectric Focusing 〈1054〉, Biotechnology-Derived Articles—Peptide Mapping 〈1055〉, and Biotechnology-Derived Articles—Polyacrylamide Gel Electrophoresis 〈1056〉.