Serum preparation and methods for the large-scale production of IgG monoclonal antibody

In this study we demonstrated that fetal calf serum (FCS) depleted of IgG by protein G affinity chromatography (G-FCS) is superior to whole FCS or serum-free culture media as a culture supplement for the production of purified IgG monoclonal antibodies (MAb). One hundred ml FCS was applied to a 25 ml protein G Sepharose 4 Fast Flow Column, which was shaken gently for 2 days at 4° C. The procedure was repeated using a protein G column for an additional day. G-FCS was used at a concentration of 5% in RPMI 1640 medium to grow the mouse myeloma cell line P3X63.Ag8.653, which secretes an IgG-1 mouse-human chimeric monoclonal antibody (TVE-1). Cell density, viability, doubling time, and antibody production were used as indices to compare the efficacy of this medium with that of whole FCS medium, AIM-V (Gibco, USA) and other serum-free media. The results demonstrate that cell growth and antibody production in -GFCS medium did not differ significantly from that in FCS medium, but were significantly better than in the serum-free media (p<0.001). TVE-1 antibody in the spent tissue culture media was purified by 50% ammonium sulfate precipitation and Protein A affinity chromatography. An antibody that was more than 99% pure was obtained. Endotoxin analysis revealed that the IgG depletion process does not generate a significant level of endotoxin in FCS (<0.06 EU/ml). Because the IgG depletion procedure is simple and economical, and the purification procedure is simple and rapid, -GFCS medium may be an ideal serum supplement when a large quantity of purified IgG monoclonal antibody is required for in vivo clinical application.