I am running EMSA assays with my DNA binding protein and a 94 base pair oligo. I am doing a gradient where I keep the DNA conc same but increase the protein conc. I am using low salt binding buffer and MGcl2 in the mix. I am running it in a 4% PAGE gel. However all I am getting in addition to really bright bands of unbound DNA, are smears in all the lanes. and these smears keep decreasing in intensity as the protein conc increases. I dont know is thats binding or some artifact..but its consistent from gel to gel. I really need help solving this issue .....so please please help me out!