What is the primary use of agarose gel electrophoresis?

Agarose gel electrophoresis is primarily used to separate DNA fragments by size. This technique relies on the properties of agarose, a polysaccharide that forms a gel matrix when cooled. When an electric current is applied to the gel, negatively charged DNA fragments migrate towards the positive electrode. The gel's porous nature allows smaller fragments to move more easily and travel further through the gel compared to larger fragments, which encounter more resistance. This separation enables researchers to analyze the size of DNA fragments, which is crucial for various applications, including DNA fingerprinting, cloning, and verifying PCR products.

Other techniques mentioned, such as amplifying RNA sequences or synthesizing proteins, involve distinct methodologies unrelated to gel electrophoresis. Likewise, isolating viruses requires specific techniques that are different from the purpose of agarose gel electrophoresis, which is specifically designed for the separation and analysis of nucleic acids based on size.