Category Archives: Gel Electrophoresis

Comparison of TAE and TBE electrophoresis buffer

Properties TBE TAE Remarks
Buffering capacity High Low TAE become exhausted during extended or repeated electrophoresis
Migration of (double stranded) DNA Slow Fast TAE has better conductivity
Resolution High resolution long DNA fragments High resolution for Short DNA fragments TBE supports agarose cross-linking better than TAE
Enzymatic modification of gel purified DNA Poor Good Borate from TBE buffer is an inhibitor of many commonly used enzymes in molecular biology
Recovery of DNA from agarose gel Poor Good Borate from TBE buffer interacts with DNA
Integrity of DNA High Low Borate from TBE buffer inhibits many enzyme activity including DNA modifying enzymes
Cost Costly Cheaper Highly conc. TAE (50X) require less volume to be transported.
Active buffer Tris – Acetate Tris – Borate
Working conc for DNA electrophoresis 1X 0.5X


Agarose gel

  • Agarose gel can be used for the separation of nucleic acids (DNA and RNA) and high molecular weight proteins or protein complexes.
  • The process of using agarose gel to separate or fractionate biomolecules under the influence of electric field is called agarose gel electrophoresis.
  • For moderate and large sized DNA, agarose gel is the most commonly used medium in most molecular biology laboratories.
  • As the name suggest, the agarose gel is prepared from agarose.
  • Chemically, agarose is a polysaccharide, made up of alternating residues of 1,3-linked β-D-galactopyranose and 1,4-linked 3,6-anhydro-α- L-galactopyranose.