Purification of polyclonal immunoglobulin G from human serum using peptide-based adsorbents

This study presents the chromatographic purification of immunoglobulin G (IgG) from human plasma using a two-column process integrating the peptide-based adsorbents LigaGuard (TM), which captures non-Ig plasma proteins in flow-through mode, and LigaTrap (TM), which isolates IgG in bind-and-elute. Buffer composition and column loading were optimized for both adsorbents. Two process configurations were evaluated. In the first design, plasma was fed to a LigaGuard (TM) column to capture plasma proteins, the effluent was loaded on the LigaTrap (TM) column, and the bound IgG was eluted with 63.8% global recovery and 99.7% purity; in comparison, Protein G agarose afforded approximately 67% recovery and 97.2% purity. In the alternative design, the LigaGuard (TM) column was utilized to polish the LigaTrap (TM) elution stream, affording 82.3% global recovery and 98.8% purity. Collectively, these results demonstrate the potential of a fully chromatographic process for purifying polyclonal IgG from plasma feedstocks.