How do DNA fragments separate according to their size during agarose gel electrophoresis?

Step-by-step solution

DNA fragments are negatively charged molecules, so they move towards the anode under an electric field during agarose gel electrophoresis. The separation of these fragments according to their size occurs through the sieving effect provided by the agarose gel matrix. The agarose polymer forms a porous network, and smaller DNA fragments can easily pass through the pores, moving farther and faster than larger fragments. Ethidium bromide is used for visualizing the DNA, and elution is the process of extracting the sepa