Question

Difference between native and denaturing gel electrophoresis

Answer 1

SDS PAGE, we add detergent (SDS) to both the gel and loading dye (also has DTT or Beta-ME), and yeah it is boiled. This results in the denaturing of the protein. The disulfide bridges are broken (B-ME or DTT), hydrophobic core is exposed by the interaction with the hydrophobic groups of detergent and boiling completely breaks the integrity of the protein resulting in a liner polypeptide (primary structure)

In case of Native PAGE, we exclude the denaturing agents and steps. This preserves the folded structure of the protein and is migrated in the gel in its native form, thus giving the 
electrophoresis