Improved Method for Protein Quality Control

Thermo Fisher Scientific has developed a pH-gradient-based method that provides excellent resolution for monoclonal antibody (MAb) charge variants. Application Note 1092: Separation of Intact Monoclonal Antibody Sialylation Isoforms by pH Gradient Ion-Exchange Chromatography demonstrates that this approach is more convenient and straightforward than the isoelectric focusing method routinely used for protein sialylation profiling.

This new method uses a cation-exchange protein column on a biocompatible analytical liquid chromatography system; a separate project is underway that focuses on fast separation using a strong cation-exchange column that incorporates a smaller particle size.

Glycosylated proteins-including erythropoietins, MAbs, and various hormones-constitute a large portion of major approved therapeutic biological drugs. Sialic acids are important to many biological processes and also have significant effects on the properties of therapeutic proteins. Thus, monitoring protein glycosylation, including sialylation, is important for both glycoprotein characterization and quality control purposes.