Comparison of chromatographic ion-exchange resins

Abstract

A comparative study was performed on strong anion exchangers to investigate the pH dependence, titration curves, efficiency, binding strength, particle size distribution, and static and dynamic capacity of the chromatographic resins. The resins tested included Q Sepharose XL, UNO Q-1, Poros 50 HQ, Toyopearl QAE 550c, Separon HemaBio 1000Q, Q-Cellthru Bigbeads Plus, Q Sepharose HP and Toyopearl SuperQ 650s. Testing was performed with five different proteins: anti-Factor VII monoclonal antibody (immunoglobulin G), aprotinin, bovine serum albumin, lipolase and myoglobin. The dependence of pH on retention varies from generally low to very high for proteins with a low isoelectric point (pl). An unexpected binding at pH 7-8 of aprotinin with pI >11 was observed on Separon HemaBio 1000Q. No link between pH dependence on retention and titration curves of the different resins was observed. Efficiency results show the expected trend of higher dependence of the plate height with increasing flow-rate of soft resins compared to resins for medium- and high-pressure operation. No or a very small difference in particle size distribution was obtained between new and used resins. Binding to anion-exchange resins as a function of ionic strength varies to some extent depending on the specific protein. Generally, binding and elution at high salt concentration may be performed with Q Sepharose XL, Toyopearl QAE 550c, Q Sepharose HP and Poros 50 HQ, while binding and elution at low salt concentration may be performed with Q-Cellthru Bigbeads Plus. A very high binding capacity was obtained with Q Sepharose XL. Comparison of static capacity and dynamic capacity at 10% breakthrough shows approx. 50-80% utilization of the total available capacity during chromatographic operation. A general good agreement was obtained between this study and data obtained by the suppliers. The results of this study may be used for selection of resins for testing in process development.

The role of polymer nanolayer architecture on the separation performance of anion‐exchange membrane adsorbers: I. Protein separations

“…The isoelectric point (pI) of IgG is about 5.8-7.5 (Baruah et al, 2006;Hahn et al, 1998;Hemmings and Jones, 1974). Working at a pH value 1 unit greater than pI, the IgG carries a net negative surface charge and will bind to an anion-exchange stationary phase (Staby et al, 2000;Staby and Jensen, 2001). Anion-exchange membranes with four different polymer chain densities, and, thus, different spacing between polymer chains, were prepared using surface-initiated ATRP for 20 h. Volumetric flow rate was used as process variable to study the effect of linear flow velocity on the dynamic binding capacities.…”

Properties and Characterization of High Capacity Resins for Biochromatography

“…Independent of whether the functionalized resin is an IEX, HIC or affinity resin the surface modification affects their mass transfer properties, magnitude of binding capacities and sometimes non-specific interactions, which may unpredictably influencing the adsorption properties positively or negatively for an individual protein. From Staby [33] the dynamic binding capacities from different strong anion exchangers were compared for BSA, Lipolase and Anti-FVII antibody. Resins with more than 200 mg/mL for BSA have shown a very low binding capacity for Anti-FVII antibody while resins with low BSA binding capacities could be higher in the antibody binding capacities.…”

Dual salt mixtures in mixed mode chromatography with an immobilized tryptophan ligand influence the removal of aggregated monoclonal antibodies

“…While acetate and sodium chloride led to a capacity of 54 mg/mL resin, the capacity for glutamate and sodium chloride decreased to 51 mg/mL resin and the capacity with citrate and sodium chloride decreased further to 32 mg/mL resin. Lysozyme capacities are typically discussed in context of sulfo type ion exchangers, which achieve higher capacities for lysozyme [30]. Low capacities of tryptophan could be due to the lack of pH or conductivity adjustments, in order to keep up comparability for the liquid phase conditions.…”