Team:Uppsala University/Backbones

For expression of toxic genes, or simply genes where you want to be able to tune the expression level, we constructed a series of lacIq bacbones. Including the lacIq casette on the plasmid ensures that the copy number of the repression always follows that of your inserted genes, providing guranteed strong repression without inducing unneccessary metabolic load.

We have made special low copy backbones for recombination onto the bacterial chromosome. The antibiotic resistance casette is flanked by Flp recombinase recognition target sites (FRT sites), meaning that the casette can be flipped out of the chromosome after integration and selection. Since low copy plasmids still have a higher copy number than one, it can be also useful to to repress toxic genes during cloning work with the lacIq system.