ABSTRACT
Low-pressure chromatography is an essential process, often requiring several discrete steps, in the isolation of commercially important target materials in the bio-processing industry. Ion exchange is a type of adsorption chromatography and involves the adsorption of an ionic species to a solid support bearing the opposite charge. For an ion-exchange step, throughput is influenced by several factors, including the flow rate used in the various process stages, the adsorption-desorption kinetics of the medium, and the capacity of the medium. Whatman ion-exchange celluloses exhibit very fast binding kinetics, with maximal adsorption typically complete within 2 min, thus enabling the media to be used to close to their theoretical maximum capacity. The protein capacity of the ion-exchange medium is especially critical to the economic feasibility of the process. The nature and scale of the upstream stages of a process will directly determine the volume and concentration of the feedstock for the ion-exchange step.
