Dear Jerry, I've just become aware of this spin column to remove endotoxin, marketed by Generon, UK.
http://generon.co.uk/index.php?route=product/category&path=238 Good luck, Jon ________________________________________ On Wed, Mar 7, 2012 at 9:50 AM, Jerry McCully <for-crystallizai...@hotmail.com> wrote: > > > Dear All; > > We purified a His tag protein by Ni-NTA and gel-filtration from > E.coli. > > We tried two endotoxin removal resins from Pierce. However, it is > hard to remove the endotoxins in the purified protein because the protein > bound to the resin as well. > > This protein contains quite a few aromatic residues and has a pI > around 6. > > Any ideas to remove the endotoxins will be highly appreciated. > > best regards, > > Jerry McCully > >