Preliminary studies on the purification of a monoclonal antibody by affinity precipitation with Eudragit S-100

A simple procedure for the purification of an IgG-type monoclonal antibody by affinity precipitation using Eudragit S-100 is presented. The ligand, a microbial lipase previously used as antigen, was coupled to the polymer at a concentration of 40 mg lipase/g Eudragit. This macroligand was reversibly precipitated by manipulating the pH at values higher and lower than 4.8. The effects of polymer concentration and dilution of hybridoma culture supernatant on the overall precipitation process were evaluated. The best purification factor was achieved with a polymer concentration of 0.1% (w/v) and a supernatant dilution of 1:3. The preliminary studies reported here enabled the purification of a monoclonal antibody in one step with an activity yield (by ELISA) of 50%-55% and a purification factor of ca 6.