Evaluation of prototype multimodal resins using chromatographic separability

This paper employs a previously developed high-throughput parallel batch adsorption screen with sequential salt step increases to rapidly investigate a set of prototype multimodal anion- (MMA) and cation-exchange (MMC) resins. Experiments were carried out using a model protein library with varying charge and hydrophobic characteristics at several pH conditions. Partition coefficients were calculated from the batch chromatograms and fed into a column (linear salt gradient) simulator to determine peak first moments (elution salt concentration). These results enabled the calculation of one-resin separability scores, quantifying each resin's ability, at a given pH, to separate all proteins in the library. Additionally, a clustering analysis grouped resins with similar chromatographic behavior, revealing correlations between resin chemistry (e.g., functional groups and geometric presentation) and protein elution patterns. Finally, the first moment data sets were used to calculate two-resin separability scores, the ability of two resins to synergistically separate the entire set of proteins from each other. These results indicated that MMC resins containing phthalimide-based moieties in concert with guanidine-containing MMA resins were particularly useful when used in concert. Overall, the presented approach is shown to be an enabling technology for rapidly screening large numbers of ligands and operating conditions for discovery of next-generation chromatographic resins.