So once we create the genomic library, we can screen the library to detect that specific gene that we want to isolate and study. And so what we do is we take the petri dish. And on the petri dish, we basically spot the petri dish with these bacterial cells that are not infected. And then we infect each one of these spots with each one of these types of lambda phages. So this lambda phage for this spot is basically infected with this lambda phage, this spot is infected with this lambda phage and so forth. And the next step, we have to go back into the lab and we synthesize a specific type of DNA probe.