Question

Your gel is 2% agarose. If your gel was 0.2% agarose, the sample would move ___________ through the gel and into the buffer solution.

a) Faster
b) Slower
c) In reverse
d) Sideways

Answer 1

With a 0.2% agarose gel, which has larger pore size than a 2% gel, the DNA sample would experience less friction and therefore move faster through the gel.

Step-by-step explanation:

If a student is working with a gel that is 2% agarose versus one that is 0.2% agarose, the sample would move through the gel differently due to the change in pore size. According to the equation v=q Ef where v is the velocity, q is the charge of the molecule, E is the strength of the electric field, and f is friction, we know that the velocity at which DNA migrates through an agarose gel is inversely related to the friction it experiences. Since a 0.2% agarose gel would have a larger pore size compared to a 2% agarose gel, the DNA would experience less friction, allowing it to travel faster. Therefore, if your gel was 0.2% agarose, the sample would move faster through the gel and into the buffer solution.