Which one of the following statements accurately describes gel electrophoresis?

• A. It separates DNA fragments based on their size by applying an electric field to a gel matrix.
• B. It sequences DNA by incorporating fluorescently labeled nucleotides.
• C. It clones DNA fragments into plasmids for propagation in bacteria.
• D. It amplifies DNA fragments using temperature cycles and specific primers.

Answer: (A)

Verified step by step guidance

1. Understand the concept of gel electrophoresis: Gel electrophoresis is a laboratory technique used to separate molecules, such as DNA, RNA, or proteins, based on their size and charge by applying an electric field to a gel matrix.
2. Recognize the role of the gel matrix: The gel matrix, often made of agarose or polyacrylamide, acts as a sieve that allows smaller fragments to move faster and farther through the gel compared to larger fragments.
3. Identify the mechanism of separation: DNA fragments are negatively charged due to their phosphate backbone. When an electric field is applied, the fragments migrate towards the positive electrode, with smaller fragments moving more easily through the gel pores.
4. Compare gel electrophoresis to other techniques: Gel electrophoresis does not sequence DNA, clone DNA into plasmids, or amplify DNA fragments. These processes are performed by other techniques such as DNA sequencing, molecular cloning, and polymerase chain reaction (PCR), respectively.
5. Conclude that the correct description of gel electrophoresis is: It separates DNA fragments based on their size by applying an electric field to a gel matrix.