A glass plate holds the agarose gel that the sample must move through. The plate is a transparent open box with two open ends. The analyst tapes the open ends of the plate closed and then pours in liquid agarose gel. Once the gel has set, the analyst removes the taped ends and places the plate in an electrophoresis tank. The glass plate can be a variety of sizes.
The analyst places a comb (a plastic structure resembling a regular comb but with regularly spaced, thin, rectangular teeth) vertically in one end of the agarose gel while the gel cools in the glass plate. After the gel has set, the analyst removes the comb, leaving neat wells for the samples.
The electrophoresis tank is an enclosed box with no top. It is connected to a power supply. After the analyst places the glass plate into the tank, she fills up the tank with a liquid buffer to cover the gel and all the wells. The buffer encourages the electric current to run through the gel evenly. After the analyst places samples into the wells, she covers the electrophoresis tank with a transparent lid. Electrophoresis tanks can either be horizontal models or vertical models.
A power source creates an electric current that draws the sample fragments from one end of the gel toward the other end. This source is composed of an anode and cathode that are placed on either end of one side of the electrophoresis tank. The anode end attracts the sample. The tank power supply plugs into a conventional socket. The analyst can adjust the voltage emitted.
A micropipette is a tool that siphons up a predetermined amount of fluid from a sample. The analyst can choose how much sample to collect by adjusting the pipette. He can then siphon and dispense exactly that much sample.
A processed gel is visualized using cameras and specialized light sources. Ultraviolet light will show bands of DNA in an agarose gel stained with ethidium bromide dye; the image can be captured on photographic film.