Question

Which of the following is correct regarding the separation of DNA fragments during gel electrophoresis?

• A. Smallest fragment will move to the farthest point towards cathode.
• B. Smallest fragment will move to the farthest point towards anode.
• C. Largest fragment will move to the farthest point towards anode.
• D. Largest fragment will move to the farthest point towards cathode.

Answer 1

Answer: (B)

The DNA fragments formed after digestion with restriction enzymes will be separated according to their size by agarose gel electrophoresis. As electric current passes through the gel, the fragments move according to the size. The larger fragments stay close to the well (the place where the DNA loaded on to the gel), and the smaller fragments move farther down the gel's length. Being negatively charged, DNA moves towards the anode.