In article <5ln419$4es$3 at daily-planet.nodak.edu>,
chambers at plains.nodak.edu (Michael A Chambers) wrote:
> Hello everyone,
>> I would like to obtain a high-copy number plasmid encoding B-lactamase. I
> realize that many plasmids utilize this as a transfection marker.
> However, I need a construct driven by a eukaryotic promoter (e.g., a
> plasmid encoding B-lactamase driven by the cytomeglovirus promoter.)
>> Thank you very much for your help.
>> Mike
Ummm...excuse me Mike....are you looking for beta-lactamase or
beta-galactosidase?? The former is the enzyme which breaks down
penicillin/ampicillin/carbenicillin to select for bacterial transformants
while the latter is best known (in mol bio) for conversion of X-gal into
its blue colored product as employed in blue-white discrimination in
bacterial colony selection or as a transfection control for eukaryotic
cells.
Plasmids with beta-galactosidase under control by CMV/SV40/LTR promoters
are as common as snowflakes on a January morn in Alaska; if someone at
your university doesn't have one (which would be strange indeed) then
there is a number of companies which sell them (Pharmacia, Stratagene,
Promega, etc.).
Karl the hepB guy
--
Karl Fischer
tyr-2 at bones.biochem.ualberta.ca
