title: Mechanism and kinetics of protein transport in chromatographic media studied by confocal laser scanning microscopy. Part I. The interplay of sorbent structure and fluid phase conditions.
abstract: An experimental study on the interplay of sorbent structure and fluid phase conditions (pH) has been carried out examining adsorption and transport of bovine serum albumin (BSA) and a monoclonal antibody (IgG 2a) on SP Sepharose Fast Flow and SP Sepharose XL. SP Sepharose Fast Flow is characterised by a relatively open pore network, while SP Sepharose XL is a composite structure with ligand-carrying dextran chains filling the pore space. Both adsorbents have similar ionic capacity. Protein transport and adsorption profiles were evaluated using confocal laser scanning microscopy. Under all investigated conditions, BSA uptake could be adequately explained by a pore diffusion mechanism. The adsorption profiles obtained for IgG 2a, however, indicated that changes in fluid phase conditions as well as a change in the solid phase structure could result in a more complex uptake mechanism as compared to pore diffusion alone. This mechanism results in a fast transport of proteins into the adsorbent, followed by an overshoot of protein in the center of the sorbent and a setback towards a homogeneous adsorption profile.
authors.affiliation: Institut für Enzymtechnologie, Heinrich-Heine Universität Düsseldorf, Jülich 52426, Germany. j.hubbuch@fz-juelich.de
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hubbuch
authors.forename: Thomas
authors.initials: T
authors.lastname: Linden
authors.forename: Esther
authors.initials: E
authors.lastname: Knieps
authors.forename: Anders
authors.initials: A
authors.lastname: Ljunglöf
authors.forename: Jörg
authors.initials: J
authors.lastname: Thömmes
authors.forename: Maria-Regina
authors.initials: MR
authors.lastname: Kula
mesh_terms: D000327:Adsorption; D002852:Chromatography, Ion Exchange / Q000379:methods*; D007700:Kinetics; D018613:Microscopy, Confocal / Q000379:methods*; D021381:Protein Transport