In SDS-PAGE, the protein sample is first-
1
Treated with a reducing agent and then with anionic detergent followed by fractionation by electrophoresis.
2
Fractionated by electrophoresis then treated with an oxidizing agent followed by anionic detergent.
3
Treated with an oxidizing agent and then with anionic detergent followed by fractionation by electrophoresis.
4
Treated with protease then fractionated by electrophoresis.
5
Question Not Attempted