In Electrophoretic Mobility Shift Assay (EMSA), after cold probe added(5×,20×,50×) , free probe weaken in gradient. The bound DNA had no obvious change. Anyone know why?
What are we looking at here? The free probe or the protein/DNA complex? When doing an EMSA, always show the free probe AND the gel shifted protein/DNA complex on the film. If an excess of cold free probe does not reduce the protein/DNA complex then your interaction is non-specific. .