In SDS-PAGE of Proteins, …

Question

In SDS-PAGE of proteins, …
A) the proteins are unfolded while being separated.
B) the proteins are separated by size, mostly independent of their native charge.
C) large proteins move more slowly.
D) an ionic detergent is used.
E) All of the above.

Accepted Answer

SDS (sodium dodecyl sulfate) is a negatively charged detergent that can release proteins from their binding partners and unfold them into extended polypeptide chains. It also masks each protein's intrinsic charge. Consequently, during SDS polyacrylamide-gel electrophoresis (SDS-PAGE), proteins are separated mainly based on their size, and not their shape or intrinsic charge; larger proteins move more slowly because the gel matrix hinders their migration to a higher extent compared to smaller proteins.