A single rabbit has been immunized with a mixture of six different proteins: green fluorescent protein, ferredoxin-NADP oxidoreductase, NADPH-thioredoxin reductase, thioredoxin f , fructose bisphosphatase and cyclophilin. Individual IgGs were re-purified from the serum through specific interaction on small columns generated by grafting the antigen on a CNBr-Sepharose matrix. The specificity of the isolated IgG was checked by Western-blot analysis. Purified and specific IgG fractions were obtained with all antigens except thioredoxin f .