I make sure the plates are cleaned with both ethanol and AMQ before starting, and I make sure to dry them too. APS is freshly prepared each time and I pace the pout=ring so that it is not too slow or too fast. However, when the gel is run, there is no obvious problem with either the marker or the dye front. The marker is evenly resolved and the dye front migrates uniformly. Ponceau S staininf of NCM post transfer also showed crisp, clean bands wich had resolved properly. How can I avoid these ridges