Gel electrophoresis Using an enzyme called a restriction endonuclease, the DNA in a gene can be cut into fragments. Genes with mutation may give fragments of different sizes. Gel elctrophoresis is a technique used to separate the DNA fragments based on their size. It is based on the premise that the different sized fragments will move through a special gel at a different rate when an electric current is applied. Step one is to load the DNA sample in a hole or "well" at the top of the gel. In the first column or "lane", we will place our DNA sample. In the second lane, we place a sample of DNA with fragments of known sizes to use a reference. In step two, we apply the electric current and allow the fragments to move through the gel. The smaller fragments move more rapidly and are seen fruther down the lane.

Last Updated ( Friday, 22 July 2005 )