GOAT IMMUNOGLOBULIN PURIFICATION ON PHOSPHOCELLULOSE AND DEAE AFFI-GEL BLUE

We describe a method for the efficient purification of immunoglobulins G ( IgG)to near homogeneity from goat serum. This was achieved by per forming first an AS-40 fractionation on goat serum, followed by chroma tography on phosphocellulose( P11) equilibrated in citrate buffer at p H 5.7. Peak I, eluted at V-0 from P11, contained all IgG and the other serum proteins, except beta-globulins and most of the alpha-2-globuli ns, which are eluted in a second peak with 0.24 M K-phosphate in citra te buffer at pH 6.0. Peak I, concentrated and dialyzed in 20 mM K-phos phate buffer pH 8.0,was then applied onto a DEAE Affi-Gel Blue column equilibrated in the same buffer. Two peaks were obtained from this col umn :peak I,eluted at V-0 contained a pure IgG fraction,while the othe r serum proteins were in peak II. We conclude that the P11 step,perfor med under the conditions we report here,is very useful to retain the a lpha-2 and beta-globulins,which contaminate the IgG when only the DEAE Affi-Gel Blue purification step is used.