Wanted to remove >20kDa protein from lysate using ammonium sulfate so that i can purify a 18kDa protein using Ni-NTA purification. Why didn't it work?

His-tag and Ni-NTA purification for my 18kDa protein hasn't been very successful. I'm using 10mM imidazole in binding and 25mM imidazole in wash buffer. Still, I see a lot of non-specific protein...

31 May 2018 2,908 5 View