Question

You wish to detect multiple epitope binding sites on a protein that are located within the three-dimensional structure of a protein. Which technique should you choose?

1. SDS-PAGE followed by Coomassie staining

2. either Native or 2-D followed by Western with a monoclonal antibody

3. SDS-PAGE followed by Western with a polyclonal antibody

4. SDS-PAGE followed by Western with a monoclonal antibody

5. Native followed by Western with a polyclonal antibody

Answer 1

Correct option: 5. Native followed by Western with Polyclonal antibody

Explaination:

Native gel electrophoresis separates proteins based on the isoelectric point and the pH. Native gel do not contain SDS, so charge on protein is based on isoelectric point and pH. When antibody is to be used to detect the native epitope on antigen, protein should not be denatured using SDS.

Polyclonal antibody is a collection of multiple antibodies from various  B cells which recognizes multiple epitopes on the same antigen. Each individual antibody detects a unique epitope on antigen.

While monoclonal antibody is binds to single unique epitope on antigen