sodium dodecyl sulfate polyacrylamide gel electrophoresis evidence A type of gel electrophoresis evidence where proteins are separated according to their electrophoretic mobility. SDS-PAGE evidence ECO:0000333 eco 2012-07-31T02:56:43Z mchibucos Electrophoretic mobility is a function of both the length and charge of a protein. The protein sample is linearized with sodium dodecyl sulfate (SDS), an anionic detergent. Typically, polypeptides bound with SDS possess an even distribution of charge per unit mass, and subsequent fractionation is by size. gel electrophoresis evidence