So let's move on to step two. So we take these fragments, we essentially place them into a solution that denatures the double helix structure. And so now in our solution we have these single stranded individual DNA molecules and now we take them and place them into a gel electrophoresis seven. Now, if the DNA molecule isn't too large we can use the polyacrylamide gel. But if the DNA molecule is very large then we have to use a gel that has larger pore size. So we normally use anguarose gel.