When I performed gel electrophoresis, why did no bands show in the picture?

Question

What kind of mistakes could I have made? (my teacher added the substance that makes the DNA glow so that's not the problem).

Answer 1

You have to make sure that you set the electric charges on the correct side of the plate...if you set the wrong charge on the wrong side of the plate the DNA would travel to the side you already put them on, which would leave no bands in the gel.