Electrophoresis is a laboratory technique that separates charged molecules, such as DNA, RNA, proteins, or other macromolecules, based on their size, charge, and shape by applying an electric field to a medium like a gel or fluid.
Principle
Charged particles migrate toward the electrode of opposite charge—positively charged cations toward the cathode (negative) and negatively charged anions toward the anode (positive)—at rates influenced by their net charge, size, and the medium's resistance, such as gel pores acting like a sieve. The process, first observed in 1807 by Ferdinand Frederic Reuss and advanced by Arne Tiselius in 1937, relies on an electromotive force driving suspended particles through the medium.
Applications
Electrophoresis serves as a cornerstone in molecular biology for analyzing biomolecules, including separating DNA fragments for sequencing, proteins via SDS-PAGE, and nucleic acids in forensics or diagnostics. It finds use in clinical settings, proteomics, genomics, and environmental testing due to its precision and versatility across scales from small polypeptides to large DNA strands.
