PEGylated protein separations: Challenges and opportunities

PEGylation, the covalent attachment of polyethylene glycol (PEG) chains to protein, is a promising method for making an efficient protein drug [1, 2]. Several PEGylated protein drugs, such as PEGylated interferons, are already on the market and others are presently in their clinical trials [1, 2]. However, the PEGylation reaction is very product specific so that generalized or platform processes for both reaction and purification have not yet been established [3]. In the current issue of Biotechnology Journal, Gunter Allmaier and colleagues, report a modified microchip capillary gel electrophoresis (MCGE), which allows for a rapid separation (one minute) of PEGylated proteins of different degrees of PEGylation [4].