Final answer:
Gel electrophoresis is a lab technique that separates DNA fragments based on their size, using a gel matrix and an electric field to sort the fragments which are then visualized with a specific dye.
Step-by-step explanation:
Gel electrophoresis separates pieces of DNA based on size. This analytical technique utilizes a gelatin-like matrix, such as agarose or polyacrylamide, to separate DNA fragments. An electric field is applied across the gel, causing DNA molecules, which are negatively charged due to the phosphate groups in their backbone, to migrate towards the positive charge at the far end of the gel.
The pore size of the gel influences the migration rate, with smaller DNA fragments moving faster than larger ones. After running the gel, DNA fragments are visualized with a fluorescent dye specific to DNA, allowing bands of different lengths to be seen, corresponding to various molecular weights of the DNA fragments.