Dear all,

I've encountered people who refuse to freeze cells and always lyse fresh pellets.  Better protein, they say.  I've never had reason to do so myself, or even to believe in their voodoo.  Up until now, maybe.

My protein expresses well and is almost all in the soluble fraction in an expression test from a fresh pellet.  The large-scale expression from the same pellet, now frozen and thawed, yielded 90% insoluble protein.

If it's the freezing that dooms the protein, I'm happy to redo the fermentor run.  Are there other examples out there of this?

Thanks.


Andreas




--
                  Andreas Förster
     Crystallization and X-ray Facility Manager
           Centre for Structural Biology
              Imperial College London