And what this process does is it ultimately separates these three DNA fragments that came from the gene based on their physical size. So what exactly is gelatrophresis? Well, it's basically the process by which we take our fragments. We place them into a special type of porous gel and then we allow those fragments to move through the porous of the gel as a result of an electric field that exists within that gel. So we take the apparatus, we connect the apparatus to a voltage source and that creates an electric potential difference, a voltage difference between the two sides of that electrophoresis setup. And so what happens is, because we connected to our battery source, one end of that plate will have a negative charge.