A simplified process for large-scale isolation of IgG from goat serum

Immunoglobin G (IgG) is routinely used in many immunoassay systems. Whilst various laboratory-scale procedures exist for the isolation of IgG from host serum few are appropriate for scale-up. We have previously reported the improvement of an existing process for isolation of IgG from goat serum at laboratory scale (Schwartz et al., 1986) and in this study we took those improvements to pilot-scale and significantly reduced the process time and associated costs. Media fouling was reduced and product yield enhanced by utilisation of a guard column of the appropriate geometry. Isolation of pure IgG by anion-exchange chromatography was improved by selection of a suitable mobile phase and column loading parameters. Using a 10 1 column of QA52, 36 g of immunoelectrophoretically pure IgG was isolated from 7.2 1 of goat serum at an overall yield of 58%. Product recovery and purity were reproducible at pilot-scale under these conditions. A procedure for media clean-in-place (CIP) is described which also effects sterilisation and depyrogenation of the column and media.