MODEL RELEASED. DNA electrophoresis. Researcher loads a sample of DNA (DeoxyriboNucleic Acid) into an agarose gel for separation by electrophoresis. A pipette is being used to place a DNA sample into a depression or well in the gel. The sample contains many different fragments of DNA. The fragments are separated by applying an electric current across the gel. Some fragments will move faster through the gel and become separated from others over time. This allows the composition of the DNA to be observed.