Gel Electrophoresis is a separation of DNA fragments according to size, based on movement through a gel medium when an electric field is applied. This lecture briefly present on Gel Electrophoresis and overall of its process. Gel electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores.