T7 promoters and expression

[Emma Macfarlane]

Novagen who supply pET vectors which are also under T7 control sell
a cell line called BL21(DE3)pLysS which according to their blurb
"is lysogenic for lambdaDE3 which carries the T7 RNA polymerase gene
under lacUV5 control.(So it is inducible by addition of IPTG rather than
infection with M13). BL21(DE3)pLysS carries the plasmid pLysS which codes
for T7 lysozyme.  This enzyme lowers the basal expression of target genes
under T& promotional control without significantly affecting induced
expression levels."  The cells should be O.K. provided the plasmid you
are using has a ColE1 origin - which I think it does.  I haven't tried 
it myself....but it might be worth a shot?
Good luck
Emma