What is gel electrophoresis?

Gel electrophoresis is a method using a gel matrix to separate and analyze macromolecules, including DNA, RNA and proteins, based on their size and charge. By applying an electric field on the gel loaded with samples to be analyzed, larger molecules move more slowly through the gel than the smaller ones. These molecules are thus sorted and can be visualized on the gel in distinct bands.

Two types of gels are most typically used: polyacrylamide and agarose gels. Polyacrylamide gels have higher resolving power than the agarose ones, which are usually used for proteins and small fragments of DNA (5-500 bp). Agarose gels, although with lower resolution, have a wider range of separation, which can be used to separate DNA fragments of 50-20,000 bp in size.