Modification of bovine serum albumin with polyethylene glycol derivative and related analysis techniques

Monomethoxypolyethylene glycol (MPEG) was activated by N, N′-carbonyldiimidazole. The activated MPEG was characterized by element analysis and used to modify bovine serum albumin (BSA). HPLC and capillary electrophoresis were applied to analyze the modified products. Capillary electrophoresis was evaluated as a convenient technique in the analysis of MPEG-modified proteins.