Electrophoresis is important because it is used to separate macromolecules, such as DNA, RNA and proteins. Gels that are made from polyacrylamide are typically used to separate DNA and proteins based on their different sizes. Proteins are also separated based on their different charges.
When electrophoresis, also known as gel electrophoresis, is used to separate DNA molecules, a solution of the molecules is placed inside a gel. The negatively charged DNA molecules are pulled through the gel by an electric field. DNA molecules that are small move through the gel quicker than large DNA molecules. The movement of the molecules through the gel creates a series of bands. Each band is separated into DNA molecules that are a particular size. The bands that are located the farthest from the start of the gel contain the smallest fragments of DNA, while those closest to the start of the gel contain the largest fragments of DNA.
Electrophoresis is used to separate DNA fragments to get a DNA fingerprint for forensic purposes, paternity testing, checking PCR reactions and to look for evolutionary relationships among organisms. The process is also used to test for and locate genes associated with a specific disease and to distinguish between samples of genetic material.