Use replica plating on anitbiotic plates, and normal media plates. Thus you
remove the surface of the colony. Then replicate it, with a sterile disc, onto
your antibiotic plates. Colonies which the don't gro at the same position on the
antibiotic plates have lost their plasmids. This method can sereen large numbers
of colonies at a time and is very straightforward.
AKB wrote:
> suppose you have a bacterial population with resistance to two antibiotics
> on two different plasmids. the bacteria are irradiated at low doses to kill
> or inactive these plasmids. how would you isolate and collect the new
> bacterial population that is susceptible to at least one of these
> antibiotics and how could you prove their susceptibility while at the same
> time not killing them and being sure to recover a pure susceptible
> population?
