Science 16

DNA and other molecules can be separated based on size and charge using a technique called gel electrophoresis. Digested DNA (DNA cut into various sized fragments using enzymes) is run through agar gel. This gel is a microscopic matrix that traps larger pieces and allows smaller pieces to travel towards the bottom. The DNA is pulled through the gel matrix because of an electric current that runs through the gel. Each fragment leaves a visible band in the gel. Figure 1 shows the band patterns of 4 individuals, A through D.

Figure 1