SIMPLE-MODEL OF TRAPPING ELECTROPHORESIS WITH COMPLICATED TRANSIENT DYNAMICS

A simple reptation model of DNA trapping gel electrophoresis is shown to lead to surprisingly complicated transient dynamics. The DNA has a big neutral object attached to one of its ends; electrophoretic migrat ion is thus slowed by trapping when it occurs in random gels. The detr apping process is thermally driven and its dependence upon the instant aneous molecular conformation gives rise to anomalous transport proper ties in our computer simulations. The electric field affects the molec ular conformations and thus modifies the nature of the transient dynam ics in nontrivial ways. The phenomenon is analyzed in terms of a direc ted walk through a periodic lattice of traps with a broad release time distribution. For large molecular sizes, we estimate that it is actua lly impossible to reach the steady state in an (experimentally) reason able period of time.