Question

What is the criterion for DNA fragments movement on agarose gel during gel electrophoresis?

• A. The larger the fragment size, the farther it moves
• B. Negatively charged fragments do not move
• C. Positively charged fragments move to farther end
• D. The smaller the fragment size, the farther it moves

Answer 1

The correct option is D The smaller the fragment size, the farther it moves

Agarose gel electrophoresis
Agarose gel electrophoresis is the technique involving the separation of molecules based on their size and charge. For example, it is used for the separation of DNA fragments formed after treatment with endonucleases, based on their size and negative charge.

Process of agarose gel electrophoresis
Process of agarose gel electrophoresis is as follows:

• The DNA fragments and size markers are loaded onto the gel well and current is passed through the gel.
• The DNA being negatively charged, moves towards the positive electrode during gel electrophoresis.
• The smaller the size of the molecule, the faster and farther it travels and the fragments are separated.

Final answer
a. The smaller the fragment size, the farther it moves.