Question

1. what does the band at the bottom of the gel indicate after it has been run?

a. small protein b. loading dye c. large protein

Explanation:

In SDS - PAGE (Sodium Dodecyl Sulfate - Polyacrylamide Gel Electrophoresis), proteins are separated based on their molecular weight. Smaller proteins move more quickly through the gel matrix. Since the bottom of the gel is where the proteins have migrated the farthest, the band at the bottom indicates a small protein. The loading dye is a separate component (not a protein band) used to monitor the progress of the electrophoresis. Larger proteins would move more slowly and be closer to the top (where the samples were loaded initially) of the gel.

Answer:

a. small protein