title: Methods development in multimodal chromatography with mobile phase  modifiers using the steric mass action model.
abstract: The ability to predict downstream protein purification processes is of great value in the biopharmaceutical industry; saving time, cost and resources. While many complex models exist, the appropriate use of simple models can be a useful tool for rapidly designing and optimizing processes as well as for risk analysis and establishing parameter ranges. In this study, the steric mass action isotherm is success-fully employed to predict the chromatographic behavior of a multimodal anionic Capto adhere systemin the presence of various mobile phase modifiers. An experimental protocol consisting of only a few column experiments is shown to be sufficient to establish the model. Proof of concept is carried out using human insulin and bovine serum albumin which have varying degrees of hydrophobicity, charge and size. Finally, the model predictions are verified under various experimental conditions and the unique selectivity of this multimodal system is explored and compared with traditional anion exchange resins.The simple model approach described here represents a rapid and useful method for model based process development of multimodal chromatography.
authors.forename: Hanne Sophie
authors.initials: HS
authors.lastname: Karkov
authors.forename: Lars
authors.initials: L
authors.lastname: Sejergaard
authors.forename: Steven M
authors.initials: SM
authors.lastname: Cramer
mesh_terms: D000818:Animals; D002417:Cattle; D002852:Chromatography, Ion Exchange / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000302:isolation & purification*; D008962:Models, Theoretical; D012710:Serum Albumin, Bovine / Q000302:isolation & purification*
chemical_list: D007328:Insulin; D012710:Serum Albumin, Bovine