Activity 3: Guide
Other Variations
Non-denaturing PAGE
Because SDS-PAGE is a denaturing PAGE, the functionalities or binding interactions of proteins cannot be evaluated, hence, this variation, the non-denaturing PAGE also known as native PAGE is presented. In this case, we run the proteins in their native conformation to investigate enzyme activity, protein-protein interactions, and the like.
What components from SDS-PAGE do you think are removed in non-denaturing PAGE?
You can read the protocol for non-denaturing PAGE here.
Gel Shift Assay
Also known as electrophoretic mobility shift assay (EMSA) or gel retardation assay.
This assay makes use of the polyacrylamide gel and runs radioactive-labelled DNA through it with a combination of proteins. If there are protein-DNA interactions present, then we will see a shift in the migration of the band identified to be the DNA because of its radioactivity. This assay actually makes use of two techniques: running the gel and running an autoradiograph for detection of the DNA and its complexes.