Dyeing for Electrophoresis

How can a mixture of molecules, too small to be seen with even a high-powered microscope, be separated from one another? Such was the dilemma facing scientists until the development of a process that is now standard in laboratories worldwide—gel electrophoresis. Laboratories rely heavily on this proven and reliable technique for separating a wide variety of samples, from DNA used in forensics and for mapping genes, to proteins useful in determining evolutionary relationships.