2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16436We use computer simulations to study the (driven) dynamics of a charged polymer in a disordered medium, thus mimicking the setting used in gel electrophoresis. In agreement with experiments, we find that inside the gel the mobility of the polymer is only a weak function of its length N. In contrast to this, the mean entrance time into the gel, is a very strong function of N, <tau_e > \propto N^1.3, and does not show any sign of saturation with increasing N. We rationalize this effect by means of a simple model and propose an experimental setup that should allow to increase the separation ability of gel electrophoresis significantly.7 pages of Latex, 4 figuresStatistical MechanicsDisordered Systems and Neural Networkstext