Electrophoresis is a laboratory technique used to separate electrically charged molecules such as DNA, RNA or proteins according to their size and charge.

Basic principles

  • Separation environment: Molecules are placed in a gel medium (agarose, polyacrylamide) or a buffer solution.
  • Electric field: Apply an electric field to the gel/solution. Electrically charged molecules will migrate according to their electrical charge - negatively charged molecules will migrate to the positive pole (anode) and positively charged molecules to the negative pole (cathode).
  • Migration speed: Smaller molecules migrate faster through the gel than larger ones. Molecules with a stronger electrical charge will also migrate faster.
  • View: After electrophoresis, the separated molecules are visualized using various staining techniques or specific detection methods.

Types of electrophoresis

There are several types of electrophoresis, among the most used are:

  • Agarase gel electrophoresis: Mainly used to separate DNA fragments.
  • Polyacrylamide gel electrophoresis (PAGE): Used to separate proteins and small fragments of DNA or RNA. Provides higher resolution than agarose electrophoresis.
  • Capillary electrophoresis: High resolution electrophoresis forms in which separation takes place in a thin tube (capillary) instead of on a gel.

Uses of electrophoresis

Electrophoresis has a wide range of applications in different fields:

  • Medical research and diagnosis:
    • DNA analysis for diagnosis of genetic diseases, forensic identification, paternity testing.
    • Separation of blood proteins to diagnose diseases such as sickle cell disease, multiple myeloma, etc.
  • Biotechnology:
    • Purification of proteins and DNA fragments.
    • DNA sequencing.
  • Food industry:
    • Food composition analysis.
    • Identification of microbial contamination.

Further information

  • Electrophoresis is a fundamental technique in molecular biology and biochemistry.
  • Interpretation of electrophoresis results requires specific expertise, usually carried out by laboratory staff or specialised medical professionals.