NMR spectroscopy can be used to analyze the higher-order structure (HOS) of biosimilars and compare it with that of the original antibody. For this purpose, 2D 13C NMR spectra of the methyl region of the biomolecule are obtained and compared with those of the biosimilar and the original. No labeling is necessary, and this method can be applied to large molecules such as whole antibodies. Additionally, the biomolecules can be studied in the formulation buffer for formulation optimization and batch comparison. Depending on the biomolecule, approximately 1-2 mg of protein can be adequate for HOS analysis.
