Mitigation of chromatography adsorbent lot performance variability through control of buffer solution design space.

The separation of undesired product-related impurities often poses a challenge in the purification of protein therapeutic species. Product-related impurity species, which may consist of undesirable isoforms, aggregated, or misfolded variants of the desired monomeric form of the product, can be challenging to remove using preparatory scale chromatographic techniques. When using anion exchange chromatography to remove undesirable product-related impurities, the separation can be highly sensitive to relatively small changes in the chromatography operating conditions, including changes to buffer solution pH, buffer solution conductivity protein loading, and operating temperature.

Efficient on-column conversion of IgG1 trisulfide linkages to native disulfides in tandem with Protein A affinity chromatography.

Protein trisulfide linkages are generated by the post-translational insertion of a sulfur atom into a disulfide bond. Molecular heterogeneity was detected in a recombinant IgG(1) monoclonal antibody (mAb) and attributed to the presence of a protein trisulfide moiety. The predominant site of trisulfide modification was the bond between the heavy and light chains.