The standard DNA 'prism' is a gel electrophoresis column, that is, a
long tube filled with jelly through which an electric current is passed. A
solution containing the scissored stretches of DNA, all jumbled together,
is poured into one end of the tube. The DNA fragments are all electrically
attracted to the negative end of the column, which is at the other end of
the tube, and they move steadily through the jelly. But they don't all
move at the same rate. Like light of low vibration frequenc...