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].