A student attempts to transform a population of E. coli with a pBluescript plasmid. How do you advise him to identify cells that have the plasmid? Answer Plate the cells on a medium containing X-gal. Cells with plasmids will turn blue. Plate the cells on a medium with ampicillin. Cells with plasmids will grow. Plate the cells on a medium with the restriction enzyme EcoRI. Cells with the plasmid will grow. Infect the cells with bacteriophage T3. Cells with the plasmid will transcribe the inserted gene and not be able to grow. Isolate individual colonies and prepare DNA from each. Size the DNA on an agarose gel to see if plasmids are present.