Now, the slightly positive protein will be attracted to those beads, but it will also be pulled down by the force of gravity. And so, because the traction isn't that great, it will end up somewhere in the middle, below protein One, which will be at the top, because it has that very strong electric attraction to those beads. And so, over time, when this protein Three ends up at the bottom, it will end up at the bottom first. We can open our knob and collect that protein in a test tube. And likewise, we can wait longer period of time, and then we can collect protein number two in our second test tube. Now, the problem with protein One is we have to wait a very, very long time.