TBE Buffer
Encyclopedia
TBE or Tris/Borate/EDTA, is a buffer solution
containing a mixture of Tris base
, boric acid
and EDTA
.
In molecular biology, TBE and TAE
buffers are often used in procedures involving nucleic acids, the most common being electrophoresis
. Tris
-acid solutions are effective buffers for slightly basic conditions, which keep DNA deprotonated and soluble in water. EDTA is a chelator
of divalent cations, particularly of magnesium
(Mg2+). As these ions are necessary co-factors for many enzymes, including contaminant nucleases, the role of the EDTA is to protect the nucleic acids against enzymatic degradation. But since Mg2+ is also a co-factor for many useful DNA-modifying enzymes such as restriction enzyme
s and DNA polymerase
s, its concentration in TBE or TAE buffers is generally kept low (typically at around 1 mM).
TBE can be diluted to 0.5X prior to use in electrophoresis, 1x is acceptable as well.
Buffer solution
A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid. It has the property that the pH of the solution changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a...
containing a mixture of Tris base
Tris
Tris is an abbreviation of the organic compound known as trisaminomethane, with the formula 3CNH2. Tris is extensively used in biochemistry and molecular biology. In biochemistry, tris is widely used as a component of buffer solutions, such as in TAE and TBE buffer, especially for solutions of...
, boric acid
Boric acid
Boric acid, also called hydrogen borate or boracic acid or orthoboric acid or acidum boricum, is a weak acid of boron often used as an antiseptic, insecticide, flame retardant, as a neutron absorber, and as a precursor of other chemical compounds. It exists in the form of colorless crystals or a...
and EDTA
EDTA
Ethylenediaminetetraacetic acid, widely abbreviated as EDTA , is a polyamino carboxylic acid and a colourless, water-soluble solid. Its conjugate base is named ethylenediaminetetraacetate. It is widely used to dissolve limescale. Its usefulness arises because of its role as a hexadentate ligand...
.
In molecular biology, TBE and TAE
TAE buffer
TAE buffer is a buffer solution containing a mixture of Tris base, acetic acid and EDTA.In molecular biology it is used in agarose electrophoresis typically for the separation of nucleic acids such as DNA and RNA. It is made up of Tris-acetate buffer, usually at pH 8.0, and EDTA, which sequesters...
buffers are often used in procedures involving nucleic acids, the most common being electrophoresis
Electrophoresis
Electrophoresis, also called cataphoresis, is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. This electrokinetic phenomenon was observed for the first time in 1807 by Reuss , who noticed that the application of a constant electric...
. Tris
Tris
Tris is an abbreviation of the organic compound known as trisaminomethane, with the formula 3CNH2. Tris is extensively used in biochemistry and molecular biology. In biochemistry, tris is widely used as a component of buffer solutions, such as in TAE and TBE buffer, especially for solutions of...
-acid solutions are effective buffers for slightly basic conditions, which keep DNA deprotonated and soluble in water. EDTA is a chelator
Chelation
Chelation is the formation or presence of two or more separate coordinate bonds between apolydentate ligand and a single central atom....
of divalent cations, particularly of magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
(Mg2+). As these ions are necessary co-factors for many enzymes, including contaminant nucleases, the role of the EDTA is to protect the nucleic acids against enzymatic degradation. But since Mg2+ is also a co-factor for many useful DNA-modifying enzymes such as restriction enzyme
Restriction enzyme
A Restriction Enzyme is an enzyme that cuts double-stranded DNA at specific recognition nucleotide sequences known as restriction sites. Such enzymes, found in bacteria and archaea, are thought to have evolved to provide a defense mechanism against invading viruses...
s and DNA polymerase
DNA polymerase
A DNA polymerase is an enzyme that helps catalyze in the polymerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best known for their feedback role in DNA replication, in which the polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand....
s, its concentration in TBE or TAE buffers is generally kept low (typically at around 1 mM).
Recipe (1 liter of 5X stock solution)
- 54 g of Tris baseTrisTris is an abbreviation of the organic compound known as trisaminomethane, with the formula 3CNH2. Tris is extensively used in biochemistry and molecular biology. In biochemistry, tris is widely used as a component of buffer solutions, such as in TAE and TBE buffer, especially for solutions of...
(CAS#CAS registry numberCAS Registry Numbersare unique numerical identifiers assigned by the "Chemical Abstracts Service" toevery chemical described in the...
37186) - 27.5 g of boric acidBoric acidBoric acid, also called hydrogen borate or boracic acid or orthoboric acid or acidum boricum, is a weak acid of boron often used as an antiseptic, insecticide, flame retardant, as a neutron absorber, and as a precursor of other chemical compounds. It exists in the form of colorless crystals or a...
(CAS# 11280) - 20 ml of 0.5 M EDTAEDTAEthylenediaminetetraacetic acid, widely abbreviated as EDTA , is a polyamino carboxylic acid and a colourless, water-soluble solid. Its conjugate base is named ethylenediaminetetraacetate. It is widely used to dissolve limescale. Its usefulness arises because of its role as a hexadentate ligand...
(CAS# 60004) (pHPHIn chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
8.0)
TBE can be diluted to 0.5X prior to use in electrophoresis, 1x is acceptable as well.
See also
- LB bufferLB bufferLithium Borate buffer is a buffer solution used in agarose electrophoresis, typically for the separation of nucleic acids such as DNA and RNA. It is made up of Lithium borate ....
, lithium borate buffer, a similar buffer containing lithium ions in place of Tris - TAE bufferTAE bufferTAE buffer is a buffer solution containing a mixture of Tris base, acetic acid and EDTA.In molecular biology it is used in agarose electrophoresis typically for the separation of nucleic acids such as DNA and RNA. It is made up of Tris-acetate buffer, usually at pH 8.0, and EDTA, which sequesters...
, a similar buffer containing acetic acid in place of boric acid