Merck
HomeApplicationsGenomicsNucleic Acid Gel Electrophoresis

Nucleic Acid Gel Electrophoresis

DNA electrophoresis using an agarose gel

Nucleic acid gel electrophoresis is a molecular biology technique for the separation, identification, and purification of DNA and RNA fragments based on size and charge. In this technique, DNA and RNA molecules are separated by applying an electric field to move negatively charged nucleic acids through an agarose or polyacrylamide gel matrix.  

The gel matrix acts as a sieve, allowing shorter molecules to run more quickly through the pores of the gel than longer molecules. 

  • Agarose gels are more commonly used for DNA and RNA electrophoresis and can resolve DNA fragments ranging from 50 base pairs (50 bp) to 50,000 bp using standard electrophoretic techniques.
  • Polyacrylamide gels have a smaller range of separation and can resolve fragments of DNA less than ~500 bp with very high resolution.
  • Both agarose and polyacrylamide gels can also be used in electrophoretic mobility shift assays (EMSA) to characterize protein-nucleic acid interactions. 

Following electrophoresis, DNA and RNA molecules can be visualized via the use of stains or UV light, extracted and purified from the gel, or transferred for blotting. These methods are common preparative techniques in cloning, PCR, mass spectrometry, next generation sequencing (NGS), and Northern and Southern blot applications and workflows.


Related Technical Articles

  • Ethidium bromide is a well-known and widely used fluorescent dye in biotechnology research.
  • An ultrafiltration cartridge can be placed at the outlet of a water purification system to deliver nuclease-free ultrapure water.
  • Nuclease-free water (or PCR water) is needed in molecular biology to avoid sample degradation during PCR, sequencing, etc. Ultrafiltration provides a quicker, safer, and more sustainable alternative to DEPC treatment when preparing RNase-free and DNase-free water.
  • Learn how water impurities can affect pH. Water quality defined as pure water or Type 2 water is recommended to prepare buffer solutions or measure pH.
  • We offers a variety of markers that aid size determination of samples separated by agarose and/or polyacrylamide gel electrophoresis. These products include markers for DNA, PCR fragments and RNA and can be concurrently run with the samples. All the markers stain well with common nucleic acid stains.
  • See All (6)

Related Protocols

Find More Articles and Protocols





Sign In To Continue

To continue reading please sign in or create an account.

Don't Have An Account?