Question

How do you find the molecular weight for the band of interest in gel electrophoresis?

Answer 1

To determine the molecular weight of an unknown protein, you should separate the sample on the same gel with a set of molecular weight standards. After running the standards and the unknown protein sample, the gel is processed with the desired stain and then de-stained for about 12 to 14 hours to visualize the protein bands.

After running the gel, you should then determine the relative migration distance (Rf) of the protein standards and the unknown protein. The migration distance can be determined using the following equation:

Rf = migration distance of the protein
Migration distance of the dye front