help protein concentration

[Randy Willis]

Mark Bryant wrote:

>How can I concentrate a purified, recombinant His-tagged protein to near
>10mg/ml without it precipitating out of solution? Any tips on buffers or salts to try?

Mark,

  I'm not sure that I understand the problem.  In our group, we
routinely concentrate his-tagged proteins to well over 10mg/ml using
centrifuge concentrators from Millipore and Amicon (now the same
company) without difficulty.  We're an NMR lab, so concentration is
critical.

Good luck, 

Randall C Willis, Researcher
Biochemistry, Hosp for Sick Children
3522-555 University Ave
Toronto, ON
M5G 1X8  CANADA

416-813-5933 (ph)  -5022 (fax)

willis at gandalf.psf.sickkids.on.ca