Hi Eric, If you are trying to express your Se-Met protein, it is typically done in a defined media starting with a minimal media base so a mixture of amino acids, particularly those that are essential, is needed. You likely will not get very high yields of SeMet-labeled protein if you simply add SeMet to a rich media like LB or TB, etc. for expression.
The B834 auxotroph is not necessary, however. We typically use standard BL21(DE3) cells and follow the procedure by Studier FW. Protein Expr Purif. 2005 May;41(1):207-34 (http://www.ncbi.nlm.nih.gov/pubmed/15915565) to get high yields of SeMet protein. Still requires a defined media though. good luck, Eric ================================ Eric T. Larson, PhD Biomolecular Structure Center Department of Biochemistry Box 357742 University of Washington Seattle, WA 98195 email: larso...@u.washington.edu ================================ On Sat, 30 Apr 2011, <Eric Karg> wrote:
Dear all, I want to make a Se-Met-labeled protein using the Met auxotroph strain B834. All the protocols I've found require addition of aa-mix. Has anyone expressed in this strain without the aa-mix? Any ideas and suggestions? Thanks in advance! Eric
