Isolation and Characterization of IgG from Human Serum, a Comparative Study on Different IgG Purification Methods

Munish Kumar. D, Chandrashekar. B, Ramakrishna. M , Sukumaran. M.K

In the present investigation IgG from serum sample was purified by Ammonium sulfate ((NH4)2SO4) fractionation, Protein A and Thiophilic affinity chromatography in order to select a method that can be used for further studies. Among the three methods employed, Protein A affinity chromatography was the best method both in terms of purity and protein concentration. Presence of IgG in (NH4)2SO4) fractionation, Protein A and Thiophilic affinity chromatography fraction were confirmed by direct ELISA using goat anti human IgG-HRP conjugate. The molecular weights of (NH4)2SO4) fractionated IgG, Protein A and Thiophilic affinity chromatography purified IgG were found to be 28 and 52 kDa respectively.