Application of capillary electrophoresis-sodium dodecyl sulfate in assessing the purity of monoclonal antibody biopharmaceuticals

Monoclonal antibodies (mAbs) are emerging biopharmaceuticals that have drawn great public attention due to their potential to treat many thorny diseases such as cancers, infections, autoimmune disorders and transplant rejection. However, because their production typically relies on biological means and their biological nature is giant and complex proteins, they are prone to be contaminated by impurities introduced during the production process or generated due to the instability of the products themselves. Both process-related and product-related contaminants need to be strictly monitored throughout the entire process from production to consumption. CE-SDS is a canonical method widely used to determine the purity of biopharmaceuticals like mAbs. Compared with early techniques such as SDS-PAGE, it can separate components of different sizes in the analytes in a quick and precise manner. In this review, we demonstrate the principle underlying the function of CE-SDS and summarize the applications of CE-SDS in assessing major types of impurities. We will also discuss the limitations and advantages of CE-SDS compared with other techniques to point out potential directions for future research.