Bond fluctuation method for a polymer undergoing gel electrophoresis

We present a computational methodology for the investigation of gel electro phoresis of polyelectrolytes. We have developed the method initially to inc orporate sliding motion of tight parts of a polymer pulled by an electric f ield into the bond fluctuation method (BFM). Such motion due to tensile for ce over distances much larger than the persistent length is realized by non local movement of a slack monomer at either end of the tight part. The latt er movement is introduced stochastically. This new BFM overcomes the well-k nown difficulty in the conventional BFM that polymers are trapped by gel fi bers in relatively large fields. At the same time it also reproduces proper ly equilibrium properties of a polymer in a vanishing field limit. The new BFM thus turns out to be an efficient computational method to study gel ele ctrophoresis in a wide range of the electric field strength. [S1063-651X(99 )01401-4].