The comb is removed from the solidified gel and the DNA is loaded into the wells left by the comb. TBE into the chambers and placing the gel in the box. EtBr intercalates into the DNA and fluoresces when it is exposed to ultraviolet light. EtBr is a mutagen and must be handled carefully . The samples are loaded into the agarose gel wells and then electrophoresed by connecting the gel box to a power supply.
Electrophoresis is a laboratory technique used the to separate charged molecules.
DNA is negatively charged and moves, under the force of an electric current, through the matrix of the agarose. Molecules separate by size, with the smaller ones moving more rapidly through the gel than the large ones. The EtBr binds to the DNA during electrophoresis. When the gel is exposed to UV light, the DNA bands fluoresce in a distinctive pattern of DNA fragments, one band for each different size fragment. We take a photograph of the gel so that it is easier to study the banding pattern.