Double Labeling Problem

[Michael Szardenings]

In article <4g8og1$jh7 at news.fsu.edu>, srd9025 at garnet.acns.fsu.edu. says...
>
>I am double labeling a protein grown in E. coli.  I am labeling with 15N 
>and 13C.  The 15N label is working fine by itself. I get a good amount 
>of protein, but when I tried to double label the growth basically died.  
>I am introducing the 13C through glucose.  Has anyone else had this 
>problem?  Suggestions of possible problems would be welcome.
>
Perhaps you use too much glucose? 1% is sometimes already a problem for 
certain strains, but 2% will definitely kill E.coli. There is some effect on 
the ATPase, that makes glucose also a very good conserving agent for 
marmelades etc (which is a field that actually not belongs to this list, 
sorry).
Regards
		Michael
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