And these two categories basically require slightly different methods. So let's begin with method number one, by which we essentially modify our plasmid by removing a large segment of DNA from that plasmid. And the way that we carry out this process is so we take our plasmid. So remember, the plasmid is this circular, double stranded DNA molecule. And let's suppose we want to delete, we want to remove this entire chunk of DNA shown by purple. So to remove this, all we really have to do is take those specific restriction enzymes that cleave at this position.