Electrophoresis

What is electrophoresis? Electrophoresis, more specifically gel electrophoresis is a method used to separate DNA fragments or protein molecules of different size through a gel matrix using an electric current. In most cases the gel used for this technique is made up of a crosslinked polymer. This gel has pores through which the particles of DNA or proteins move. The gel is placed in a buffer filled box and an electrical current is applied. Some people refer to separating DNA fragments as DNA gel electrophoresis or agarose electrophoresis. Protein electrophoresis refers to the separation of proteins through a gel matrix. Proteins differ greatly in charge and shape therefore they must be denatured by a detergent such as sodium dodecyl sulfate. This coats the protein with a negative charge allowing it to respond to the electrical field in the box. Separating proteins using this method is sometimes referred to as SDS electrophoresis but more commonly known as SDS-PAGE or sodium dodecly sulfate -polyacrylamide gel electrophoresis. Once the proteins have been separated one can perform electrophoresis analysis. Ethidium bromide is used to stain DNA and fluoresces orange when exposed to UV light. Companies like Promega, Bel-Art, and Labnet distribute supplies used for this technique.