3.1.3 Affinity chromatography
Affinity chromatography, a significant protein purification advancement, enables the study of protein degradation, post-translational changes, and interactions. It relies on an interaction between an immobilized affinity ligand and target proteins needing purification. Ligands like dextran, polyacrylamide, or cellulose attach to the column-filling material. Specific proteins form complexes, binding to the matrix and adhering to the column. Unbound proteins pass through, and the bound protein elutes with ionic strength changes due to pH or salt addition [15].
In recent decades, various affinity chromatography techniques, including IMAC, immunoaffinity, heparin, and lectin, have been explored for lab-scale vaccine purification, offering promising results and higher yields than alternatives like ultracentrifugation. Additional ligands like dye ligands for virus and toxin purification, sugar ligands for toxin purifications, and novel methods for pDNA and vaccine antigen purification have been investigated [23].
However, challenges hinder industrial-scale implementation, including large-scale ligand production, composition limitations, raw material availability, lack of high-productivity chromatographic media, and standards for column disinfection and cleaning [23].