What is the primary function of gel electrophoresis in DNA analysis?

The primary function of gel electrophoresis in DNA analysis is to separate DNA fragments by size. This technique utilizes an electric field to move DNA fragments through a gel matrix, typically made of agarose or polyacrylamide. Since DNA is negatively charged, it migrates towards the positive electrode. Smaller fragments of DNA can navigate through the gel matrix more easily than larger ones, leading to a separation based on size.

This ability to effectively separate and visualize DNA fragments makes gel electrophoresis a critical tool in various applications, such as checking the results of PCR (polymerase chain reaction) amplification, assessing the size of restriction enzyme digests, and preparing samples for further analysis or sequencing.