Endotoxin removing alternatives

Hello,

I would like to get suggestions and tips on which methods I should use to remove completely the endotoxin on a recombinant protein expressed in E.coli.

In fact, the protein I've purified was found to be contaminated by LPS. As I intend to use it in studying the immune response of Bone marrow-derived macrophage and other macrophages cell lines, the contaminating LPS will interfare with my results.

I plan to use the Detoxi-Gel removing gel from Thermo scientific. Will anyone tell me, what I should expect as result (the kit ensure to remove 1 ml of gel removes >9,995 EU from a 10,000 EU challenge of LPS (greater than 99% efficiency)). What is the minimal endotoxin contamination should I target to expect a non-interference with my experiment?

Thanks