And so that's a very convenient property because if we have this polylinker, we can essentially insert any type of DNA fragment that we wish to. And once we insert that fragment, it will essentially inactivate this gene that codes for the beta galacticadase molecule. And if this gene is inactivated, then what that means is the cells that do uptake this plasmid will not have the ability to turn our solution blue. And so if the solution in a beaker becomes blue, that means the cells did not uptake that plasmid. But if the solution does not turn blue, that means the cells successfully uptook that particular plasma because this gene has been inactivated. And we'll talk more about different examples and different experiments that involved with these different plasmids in a future lecture.