Nucleic acid gel electrophoresis is a molecular biology technique for the separation, identification, and purification of DNA and RNA fragments based on size and charge. In this technique, DNA and RNA molecules are separated by applying an electric field to move negatively charged nucleic acids through an agarose or polyacrylamide gel matrix.
The gel matrix acts as a sieve, allowing shorter molecules to run more quickly through the pores of the gel than longer molecules.
Following electrophoresis, DNA and RNA molecules can be visualized via the use of stains or UV light, extracted and purified from the gel, or transferred for blotting. These methods are common preparative techniques in cloning, PCR, mass spectrometry, next generation sequencing (NGS), and Northern and Southern blot applications and workflows.