protein purification - (Sep/22/2005 )

after FPLC purification. I do get my target protein in a strong band from 300ml culture, but unfortunately also have lots of small bands down there. I did protein purification before, no problem at all. I am thinking is it my washing step not enough? or anyelse you might think? help me. this purification thing pull my hair off.

Thanks
cathy

The smaller bands might be degradation products from your main protein. DO you use protease inhibitors?

What kind of purification are you doing?