Selecting Lethal Mutants? - (Aug/12/2010 )

Hi all, I was wondering if you could lend your brain power! I'm trying to think of a way of selecting lethal mutations in a randomly transposon mutated bacterial sample. The transposon would contain a resistance cassette for selection of mutated bacteria, however the lethal mutations are probably gonna be the most interesting ones and am trying to think of a way to be able to see what genes have been disrupted even though, by definition, I can't proliferate my lethally mutated bacteria.

I can't see personally how it could be done but thought maybe the bioforum boffins would be able to prove me wrong!

Conditional selection? i.e. have some system whereby the mutations are not lethal unless turned on? I don't really see how this can be done with a whole genome system though.