Purification of non-mAb biologics : development of integrated purification processes

Abstract

The first strategy employed for purification process development consisted of identifying affinity peptides for use as chromatographic ligands to selectively capture desired product directly from cell culture fluid. In this strategy, epitope mapping of known target binding partners was used to generate an initial library of peptides. Further, phage display screening with negative selection was used to identify additional peptides to supplement the library of initial peptide candidates. Using immobilized peptide microarrays, the library of candidates was screened to evaluate the affinity and selectivity of the peptides towards granulocyte colony-stimulating factor. Lead peptide candidates identified by this screening method were further evaluated in fluorescence polarization assays to determine their ability to be utilized as affinity ligands.