Histag protein purification problem

[Dr. Thomas T. chen]

I used pET system to express histag  fused peptide in BL21 (DE3). When I
purified the fusion peptide by MCAC, I found other bacterial proteins
sticking to the column tightly. I tried to use thrombin to cut the fusion
peptide in order to purify the target peptide, but without success. Can
anyone give me suggestion how to purify my target peptide?
 Thank  in advance.


My email address: Zhang at Biotek.mcb.uconn.edu