Wybór antybiotyku

Antibiotic selection is typically used to ensure that a bacterial colony contains a plasmid with a few key features, an antibiotic resistance gene and a gene of interest that a researcher wants to express.

For the bacteria to uptake the plasmid, both must be incubated together and then, undergo heat shock to promote incorporation. Not every bacterium will successfully uptake a copy of the plasmid.

As the goal is to isolate bacteria that possess a copy, researchers add some of the bacterial culture onto a plate containing an antibiotic. Only those bacteria that have taken up the plasmid, which contains the resistance gene, will be able to degrade the antibiotic and grow on the plate.

Over the next few days, single bacterium will form colonies, which can then be selected for further work.