By Adding SDS (Sodium Dodecyl Sulfate) During the Electrophoresis of Proteins

Question

By adding SDS (sodium dodecyl sulfate) during the electrophoresis of proteins, it is possible to:
A) determine a protein's isoelectric point.
B) determine an enzyme's specific activity.
C) determine the amino acid composition of the protein.
D) preserve a protein's native structure and biological activity.
E) separate proteins exclusively on the basis of molecular weight.

Accepted Answer

By adding SDS during electrophoresis, proteins are denatured and uniformly charged with negative charges. This allows for separation of proteins based on their molecular weight, as the only factor that affects their migration through the gel is the size of the protein. This technique is called SDS-PAGE (polyacrylamide gel electrophoresis), and it is commonly used in protein chemistry and biochemistry.