title: Experimental design of a twin-column countercurrent gradient purification process.
abstract: As typical for separation processes, single unit batch chromatography exhibits a trade-off between purity and yield. The twin-column MCSGP (multi-column countercurrent solvent gradient purification) process allows alleviating such trade-offs, particularly in the case of difficult separations. In this work an efficient and reliable procedure for the design of the twin-column MCSGP process is developed. This is based on a single batch chromatogram, which is selected as the design chromatogram. The derived MCSGP operation is not intended to provide optimal performance, but it provides the target product in the selected fraction of the batch chromatogram, but with higher yield. The design procedure is illustrated for the isolation of the main charge isoform of a monoclonal antibody from Protein A eluate with ion-exchange chromatography. The main charge isoform was obtained at a purity and yield larger than 90%. At the same time process related impurities such as HCP and leached Protein A as well as aggregates were at least equally well removed. Additionally, the impact of several design parameters on the process performance in terms of purity, yield, productivity and buffer consumption is discussed. The obtained results can be used for further fine-tuning of the process parameters so as to improve its performance.
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Fabian
authors.initials: F
authors.lastname: Steinebach
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Ulmer
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Lara
authors.initials: L
authors.lastname: Decker
authors.affiliation: ChromaCon AG, Zurich, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Aumann
authors.affiliation: Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland. Electronic address: massimo.morbidelli@chem.ethz.ch.
authors.forename: Massimo
authors.initials: M
authors.lastname: Morbidelli
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis / Q000302:isolation & purification*; D002852:Chromatography, Ion Exchange / Q000295:instrumentation / Q000379:methods*; D020033:Protein Isoforms / Q000032:analysis / Q000302:isolation & purification; D012107:Research Design; D012997:Solvents / Q000737:chemistry; D013205:Staphylococcal Protein A / Q000737:chemistry / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D020033:Protein Isoforms; D012997:Solvents; D013205:Staphylococcal Protein A
keywords: Charge isoforms; Continuous chromatography; MCSGP; Monoclonal antibody