title: Structural and functional characteristics of virgin and fouled Protein A MabSelect resin cycled in a monoclonal antibody purification process.
abstract: The structural and functional characteristics of the Protein A MabSelect resin are determined for a virgin sample and for samples removed from a column that had been operated in an antibody capture process which had shown losses in product recovery over fewer than 20 cycles. Compared to the virgin resin, the cycled samples show reduced porosity and apparent pore size based on inverse size exclusion chromatography while transmission electron microscopy (TEM) shows accumulation of foulants on the cycled resin. Adsorption isotherms, batch adsorption kinetics, and batch desorption kinetics, obtained using the antibody in purified form, show that the cycled samples have about 10% lower binding capacity and slower mass transfer. Confocal scanning laser microscopy shows, however, that different degrees of fouling exist for different beads in the cycled samples, which may correspond to the existence of areas exposed to minimal or no flow in the process column. Replacing the standard cleaning procedure with an improved multi-step cleaning protocol prevented the accumulation of foulants in the resin beads, as evident from TEM, and resulted in a stable operation with high recovery.
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia, 22904.
authors.forename: Shaojie
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, Virginia.
authors.forename: Kerui
authors.initials: K
authors.lastname: Xu
authors.affiliation: Pfizer, Andover, Massachusetts.
authors.forename: William
authors.initials: W
authors.lastname: Daniels
authors.affiliation: Pfizer, Andover, Massachusetts.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Salm
authors.affiliation: Pfizer, St. Louis, Missouri.
authors.forename: Judy
authors.initials: J
authors.lastname: Glynn
authors.affiliation: Pfizer, St. Louis, Missouri.
authors.forename: Joseph
authors.initials: J
authors.lastname: Martin
authors.affiliation: Pfizer, Andover, Massachusetts.
authors.forename: Christopher
authors.initials: C
authors.lastname: Gallo
authors.affiliation: Pfizer, Andover, Massachusetts.
authors.forename: Ranga
authors.initials: R
authors.lastname: Godavarti
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia, 22904. gc@virginia.edu.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Carta
mesh_terms: D000327:Adsorption; D000911:Antibodies, Monoclonal / Q000302:isolation & purification*; D055598:Chemical Phenomena; D002846:Chromatography, Affinity / Q000379:methods*; D002850:Chromatography, Gel; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D011485:Protein Binding; D013205:Staphylococcal Protein A / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D013205:Staphylococcal Protein A
keywords: Protein A resins; monoclonal antibodies; process cycling; resin fouling