So if we add the tetracycline antibiotic into that mixture, all the cells that did not successfully uptake this plasmid will essentially die. But the cells that did take up the plasma will live on. And that's exactly how we'll know that all the cells in our solution that remain alive have that plasma that contains that particular gene that we want to replicate. And then we can force those cells to divide via binary fission and that will replicate our DNA of interest. And at the end, we can extract that DNA. And now we have many, many copies of that DNA fragment.