If I have a colony with a plasmid that I've transformed onto it... is it possible to modify my plasmid with CRISPR? So that I can now purify a new modified plasmid? Is this viable?
It should be possible to make plasmid mutations with Crispr, but given that most plasmids are multi copy (cloning plasmids being hundreds per cell) you will have the problem of finding your mutant. You will not be mutating all the plasmids, but only one copy among the many hundreds. So in order to see the one you want you would need a positive selection or some trick to identify among the high background of non-mutants.