SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis, describes a technique widely used in biochemistry to separate proteins according to their electrophoretic mobility (a function of the length of a polypeptide chain and its charge) and no other physical feature. SDS is an anionic detergent applied to protein sample to linearize proteins and to impart a negative charge to linearized proteins.Synonyms: Sodium dodecyl sulfate polyacrylamide running buffer, Protein Gel Running Buffer, polyacrylamide gel running buffer.