Midi Horizontal Gel Unit (BIO 03-14)

Agarose gel electrophoresis is one of several physical methods for determining the size of DNA. In this method, DNA is forced to migrate through a highly cross-linked agarose matrix in response to an electric current. In solution, the phosphates of the DNA are negatively charged, and the molecule will therefore migrate to the positive (red) pole. There are three factors that affect migration rate through a gel: size of the DNA, conformation of the DNA, and ionic strength of the running buffer.