Although there is a limited choice of EBA resins, there are many different
conventional chromatography resins using different GMP-ready
base matrices (e.g. Sepharose, cellulose and polymethacrylate). These
matrices are paired with ligands suitable for hydrophobic interaction
chromatography (HIC), mixed-mode chromatography (MMC), sizeexclusion
chromatography (SEC, also called gel filtration), affinity chromatography
(AFC) and ion-exchange chromatography (IEC), the latter
including anion exchange chromatography (AEC) and cation exchange
chromatography (CEC) (Anonymous, 2010). Differences in the selectivity
of these ligands for target proteins and contaminating HCPs are used
to purify the target, typically usingmultiple operationswith orthogonal
separation mechanisms