How do you detect the level of colicin production by bacteria that have a colicin producing plasmid in it?

Question

If you transform a plasmid that has a colicin gene to Pseudomonas .... How do you know that the plasmid if the plasid is producing this protein ir not

Answer 1

if u transform through pbr322.

pbr322 has amphicillin and tetracyclin resistance. if u clone ur gene in any one of the resistance area then the resistance is lost. DNA is inserted into the region of pBR 322 encoding  resistance to tetracycline, transformants ( pseudomonas) still grow in ampillicin but not tetracycline. The reverse is applicable when the insert is placed within the ampillicin gene.

u can find it by culturing in a medium with both tetracycline and amphicillin

Answer 2

Two possible ways:

Use an anti-colicin antibody to determine whether it is present. .This can be quantified against known concentrations

Grow a lawn of colicin-sensitive cells and spot test with the transformed plasmid. The diameter of the clearing zone is a function of concentration