How to get rid of excess lactose in media?

[Daniel Schlieper]

Just use NZYCM (or omit the MgSO4 (= use NZYC) if you select for 
tetracycline resistance).

This medium is not inducing:
  10 g NZ amine (Type A casein hydrolysate)
   5 g NaCl
   5 g bacto-yeast extract
   1 g casamino acids
   2 g MgS04x7H2O
   1 L H20

E. coli is very happy in this medium.

I hope this helps, Daniel Schlieper

MNODA at lipovx.lbl.gov (Michael Oda) writes: Our lab has been expressing
>      some human proteins in coli, which happen to be somewhat toxic
>      to the cell. Things were going along fine and expression levels
>      were good. Suddenly the cells stopped expressing or even
>      growing in enriched media... After a month of eliminating
>      potential causes, we narrowed our problems down to the media
>      ...
-- 
Daniel Schlieper                    Institut fuer Biochemie
                                    Zuelpicher Strasse 47
Daniel.Schlieper at Uni-Koeln.De       Universitaet zu Koeln 
Tel.: +49 221 470 6443              D-50674 Koeln