Structural and functional characteristics of virgin and fouled Protein A MabSelect resin cycled in a monoclonal antibody purification process. Issue 2 (3rd September 2015)

• Record Type: Journal Article
• Authors: Zhang, Shaojie; Xu, Kerui; Daniels, William; Salm, Jeffrey; Glynn, Judy; Martin, Joseph; Gallo, Christopher; Godavarti, Ranga; Carta, Giorgio
• Is Part Of: Biotechnology and bioengineering. Volume 113:Issue 2(2016)
• Page Start: 367
• Page End: 375
• Publication Date: 2015-09-03
• Subjects: monoclonal antibodies -- Protein A resins -- process cycling -- resin fouling; Biotechnology -- Periodicals; Bioengineering -- Periodicals; 660.6
• DOI: 10.1002/bit.25708
• Languages: English
• ISSNs: 0006-3592

Abstract

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. Biotechnol. Bioeng. 2016;113: 367–375. © 2015 Wiley Periodicals, Inc. Abstract : Fouling occurs when the Protein A resin MabSelect is used repeatedly in a process cycle for mAb capture from a conditioned CHO cell culture supernatant. Transmission electron microscopy (top left) shows heterogeneously distributed foulants on the surface and in the interior of the (a) virgin, (b, c, d) cycled resin. Confocal microscopy (bottom left) shows that mAb transport in the fouled resin proceeds at different rates on different beads and is slower, on average, than in the virgin material resulting in reduced recovery.