The multicolumn countercurrent solvent gradient purification process

This article presents the multicolumn countercurrent solvent gradient purification (MCSGP) process, which uses three chromatographic columns, and incorporates the principle of countercurrent operation and the possibility of using solvent gradients. A MCSGP prototype has been built using commercial chromatographic equipment. The application of this prototype for purifying a MAb from a clarified cell culture supernatant using only a commercial, preparative cation exchange resin shows that the MCSGP process can result in purities and yields comparable to those of purification using Protein A. The second application example for the MCSGP prototype is the separation of three MAb variants using a preparative weak cation-exchange resin. Although the intermediately eluting MAb variant can only be obtained with 80% purity at recoveries close to zero in a batch chromatographic process, the MCSGP process can provide 90% purity at 93% yield. A numerical comparison of the MCSGP process with the batch chromatographic process, and a batch chromatographic process including ideal recycling, has been performed using an industrial polypeptide purification as the model system, It shows that the MCSGP process can increase the productivity by a factor of 10 and reduce the solvent requirement by 90%.