CGDP - Agarose Gels|
Agarose gels like the one shown to the left are used a lot in DNA sequencing. Remember that DNA molecules are charged and run towards positive when exposed to current. The DNA is loaded into wells which were made by a comb that was inserted when the gel was poured as a liquid. As the gel cools it hardens like jello. DNA is loaded into these wells at one end along with a loading dye (the blue in the figure) that performs two functions: 1. it gives the loaded sample more density so it sinks and stays in the well, and 2. it shows how far the sample has moved as it migrates through the gel over time.