Elektrofores

Elektrofores, or electrophoresis, refers to a family of laboratory techniques that separate charged particles in an electric field. In some languages the term elektroföres or elektroforese is used and refers to the same principle. Molecules move through a conductive medium at rates determined by their size, charge, shape, and the properties of the medium and buffer. In a typical setup, an electric potential is applied across a gel or capillary; negatively charged molecules migrate toward the anode, while positively charged species move toward the cathode.

Gel electrophoresis uses a porous matrix, most commonly agarose for nucleic acids and polyacrylamide for proteins. The gel acts as a molecular sieve, allowing smaller or more highly charged species to migrate faster, producing distinct bands that can be visualized after staining. Capillary electrophoresis places the sample in a narrow capillary; high electric fields and efficient heat dissipation enable high-resolution separations with very small sample volumes, useful for nucleic acids, peptides, and small molecules.

Detection methods include staining with intercalating dyes (for example, ethidium bromide or safer alternatives) or fluorescence labeling, followed by imaging under UV, blue light, or laser scanning. In many applications, electrophoretic separations are combined with downstream analyses such as sequencing, blotting, or mass spectrometry.

Applications range from genetic analysis and diagnostics to forensic testing and proteomics. In research, electrophoresis is used to assess molecular size, purity, and charge heterogeneity, and to monitor reactions. Historically, electrophoresis dates to early 20th century work, with developments culminating in methods for proteins and nucleic acids. Arne Tiselius received the Nobel Prize in Chemistry in 1948 for his research on electrophoresis and complexing phenomena.