Patent ID: 8222379
Filing Date: 2012-07-17
Classification: B01D,B01J,C07K

Abstract:
1. A method of separating immunoglobulin G, an ionic protein compound of interest, from a protein sample comprising protein A using a selective cation-exchange adsorbent having a sufficiently low ionic charge density to ionically bind to immunoglobulin G consisting essentially of the following steps; (a) contacting a protein sample having a conductivity between 2-6 mSi/cm and containing immunoglobulin G and protein A, with a selective cation-exchange adsorbent consisting of agarose beads having sulphopropyl groups attached thereto and having an ionic charge density from 10 to 100 μmol/ml; (b) ionically binding the immunoglobulin G to the agarose beads having sulphopropyl groups attached thereto, (c) washing the agarose beads having sulphopropyl groups attached thereto with a buffered solution to remove unbound protein A, (d) applying a salt gradient of increasing conductivity to the agarose beads having sulphopropyl groups attached thereto, and (e) eluting the ionically bound immunoglobulin G from the agarose beads having sulphopropyl groups attached thereto.