Question

What gel electrophoresis shows about DNA?

Answer 1

It generally shows its size.

Explanation:

Large pieces of DNA move though the gel more slowly, while smaller pieces move more quickly. Gel electrophoresis then allows you to separate one piece of DNA from another (assuming they are different sizes). If your DNA is supercoiled, though, it can move more quickly through a gel than it would if it were not supercoiled.