What is the difference between PAGE and SDS PAGE?
PAGE refers to polyacrylamide gel eletrophoresis and is used on proteins in their native state ..Meaning their shape can greatly influenece their ability to move through the gel matrix. So it is quite difficult or impossible to accurately assess the molecular weight of a group of proteins since they may have the same molecular weight but are strikingly different in shape ……linear or quasiliniear Vs sphereical , etc . SDS PAGE used denaturing condiitons heat and the S-S bond breaker beta-mercatoethanol or DTT, to linearize the protein berak into its subunits and the SDS to coat the protein/subunits and give them a net negative charge and a rod shape. That way these rods move toward the positive pole in accordance with their molecular size=weight. So a plot of log MW vs distance traveled compared against standards of known MW will allow fairly accurate determination of the MWs.
