We generated rabbit sera against GST fusion proteins. And then affinity purify with the same fusion protein. There are many annoying bands on western that cross react with the purified Ab in addition to the endogenous protein (Serum preabsorbed with GST, and then binds with GST-fusion protein, and finally elute with glycine from column). Should I try like making His-tagged fusion protein and expressed in different E. coli, and affinity purify antibody that generated with GST-fusion protein?
Thanks for your helps.