And instead of fragment number two, we can place some type of target DNA molecule that we actually want to copy. And we can connect these two fragments onto the size of the target DNA molecule so that the actual size of the DNA does not change compared to the DNA of that lambda phage that we initially extracted. Now, how can we connect these two fragments or these three fragments? Well, we can use a special enzyme, special catalytic protein known as DNA ligase. So what DNA ligase does, as we'll see in a future lecture, it basically uses ATP molecules to create phosphodiasta bonds between the fragments here and this fragment here. And so ultimately, when we mix these three fragments with DNA ligase, we produce recombinant DNA that is about the same size as this original DNA molecule that came from that lambda phage.