Native gel electrophoresis is a method by which proteins are separated on a gel without having been denatured or treated with a chemical called SDS, or sodium dodecyl sulphate. Native gel electrophoresis varies from denaturing gel electrophoresis in that the proteins analyzed remain folded and retain their charges.
Both types of gel electrophoresis operate using the same basic principle. Protein samples are loaded into the top of a polyacrylamide gel. An electric current is passed through the gel, and the proteins migrate through the gel. In denaturing gels, the proteins are coated with SDS, which gives them a strong negative charge. As a result, denatured proteins migrate through the gel based primarily on their molecular weight.
In native gel electrophoresis, the proteins are still folded, so the shape of the protein affects how quickly it travels through the gel. The proteins also retain their native electrical charge, and therefore the different charges will affect how the protein runs through the native gel.
Native gel electrophoresis is used to study binding to other compounds, aggregation and conformation. Native gels are necessary for many of these techniques, as denaturing protein causes it to lose its structure and any binding affinities it may have. The last benefit of native gel electrophoresis is that it is possible to extract the proteins after running the gel.