So we can use them to analyze and study some DNA molecules that we're interested in. We can also actually use them to determine the actual sequence of nucleotides of very, very long DNA molecules. So if we have a long DNA molecule, we can use these restriction enzymes to cut the molecule to smaller fragments and then we can determine what the sequence is of the smaller fragments. And by piecing together, by determining the order of the fragments, we can then determine what the order of the sequence of nucleotides is in that long DNA molecule. Now, we can also use restriction enzymes to create recombinant DNA molecules and then we can actually clone and amplify those molecules if we want to. And there are many other purposes, as we'll see in the next several lectras.