Electrophoretic mobility and conformational changes of DNA in agarose gels

摘要

We present observations of the time-dependent electrophoretic mobility and conformational changes of a polyelectrolyte, DNA, in agarose gels under an applied electric field. The short-time averaged electrophoretic mobility can be measured by means of movement of fluorescence pattern after photobleaching (MOFPAP), while the average conformational change of an assembly of polyelectrolyte chains can be revealed by means of transient electric birefringence (TEB) which measures the rise and fall of the time-dependent optical anisotropy of the polyelectrolyte chains under an applied electric field. The results from a combination of the two techniques (MOFPAP and TEB) are discussed in terms of its implications on the mechanisms responsible for pulsed-field gel electrophoresis.