These two fragments are about the same size. Then the next fragment and the smallest fragment, fragment number one. So let's take a marker and let's label these just so we know. So this is fragment number one, fragment number two, fragment number three, fragment number four and fragment number five. So this is what gel electrophoresis is. Now, when we're, we'll get into biochemistry, we're going to see that we can use gel electrophoresis not only for DNA molecules, but we can also use for proteins.