<prompt> In SDS-PAGE Sodium Dobecyl Sulfate-polyacrelamide Gel Electrophoresis proteins are separated on basis ofMassChargeDensityMolecular weight  <response>: SDS PAGE electrophoresis is a variant of PAGE. separation of molecules will depend mainly on their molecular size. Hence it is mainly used for molecular weight determination as well as for assessing purity of proteins.Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 447 