I am trying to purify some fusion protein expressed in E.coli by IMAC. But unfortunately, purified protein formed some kind of soluble aggregation , and non-reduced SDS-PAGE showed all purified stuff stay at the top of lane, and only reduced SDS-PAGE can detcted monomer of my fusion protein.
Anyone can give some suggestion for solving this problem?
Thanks.

Have you tried diluting the sample? Next try heating or urea treatment to denature the aggregates. there are several threads on this board discussing aggregation problems, easy to find with the search the site option.

Rb

zhgliu73 said:

I am trying to purify some fusion protein expressed in E.coli by IMAC. But unfortunately, purified protein formed some kind of soluble aggregation , and non-reduced SDS-PAGE showed all purified stuff stay at the top of lane, and only reduced SDS-PAGE can detcted monomer of my fusion protein. Anyone can give some suggestion for solving this problem? Thanks.