Hi Jerry, We have used 0.05% Triton X-100 in our wash buffer to wash the protein on column (Ni-IMAC for His-tagged proteins and MabSelect for antibodies). 20 column-volumes wash followed by 20 column-volume wash without detergent is typically enough to reduce the endotoxin significantly. I would also suggest checking your FPLC system, and decontaminate with 2N NaOH if neccessary. Hope that helps Regards, ray
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 > >
