Prok. expression vectors; anything that is not based on Lac operon and Amp R?

[Hedrick Lab]

Mikhail:

Thanks for the info.  A couple of additional questions... You say that 
you MUST use another origin of replication, yet I've heard from various 
sources that it is possible to get both plasmids in if you simply 
maintain the necessary drug selection.  Is this efficiency just very 
low?  

Secondly, which of the plasmids that you mentioned (i.e. with a replicon 
distinct from ColE1) are high copy number?  I'd like to get decent 
expression in the bugs, so I'd assume that having the high copy number 
would help.

Thanks again for all of the tips.

Craig Walsh