It's been a while since I posted on BioForum!
I'm having a problem I didn't anticipate. I'm purifying a protein from E. coli (Rosetta) tagged with 6xHis-SUMO.
I have a band roughly where I expect it to be in the lysate, but when I mix with my Ni-NTA beads and elute I have an odd pattern.
I get a huge band roughly the size of SUMO, and only a very small band at the expected size. My lysis buffers all have protease inhibitor cocktail added.
This is the 1st time I've ever tried to purify protein from bacterial cells so I'm really at a loss as to what my problem is. Any help would be appreciated!
All the best,