[ccp4bb] FW: endotoxin removal

[Jerry McCully]

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