Two kinds of charged molecule migrate in through a gel medium under the influence of an electrical field. This can be modeled by random walk in which one kind of molecule jumps to the right with probability p1 >e; 0.5 and the other kind of molecule jumps to the right with probability p2 >e; 0.5. The numerical experiment below illustrates the case in which p1 = 0.65 and p2 = 0.80. We allow the molecules to do their random walk for 100 steps. Note that there is a barely perceptible separation of the two molecular species. We should let the experiment run longer to get separation, e.g., for 200 steps.