Final answer:
Proteins are separated on the basis of mass during SDS-PAGE after treatment with SDS and beta-mercaptoethanol, as these agents denature proteins and negate their native charges. The correct option is a) Mass
Step-by-step explanation:
When polyacrylamide gel electrophoresis (PAGE) is carried out after subjecting a sample to SDS (sodium dodecyl sulfate) and beta-mercaptoethanol, proteins will be separated on the basis of their mass.
SDS functions as a detergent that denatures proteins, ensuring they are uniformly coated with a negative charge and thus masking their native charge. Beta-mercaptoethanol is used to reduce disulfide bonds to further ensure denaturation.
As a result, during SDS-PAGE, the only factor affecting protein migration through the gel is the molecular weight (or mass) of the protein, as proteins are forced to migrate through a polyacrylamide matrix under an electric field, with smaller proteins moving faster and further than larger ones. The correct option is a) Mass