TBE buffer
TBE or Tris/Borate/EDTA, is a
EDTA
.
In molecular biology, TBE and
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 enzymes and DNA polymerases, its concentration in TBE or TAE buffers is generally kept low (typically at around 1 mM
).
More recently discovered substitutes for TBE and TAE buffers for electrophoresis are available.[1]
Recipe (1 liter of 5X stock solution)
- 54 g of Tris base (CAS# 77-86-1, free base)
- 27.5 g of boric acid (CAS# 10043-35-3)
- 20 ml of 0.5 M EDTA (CAS# 60-00-4) (pH8.0)
Adjust pH to 8.3 by HCl.[2]
TBE can be diluted to 1X prior to use in electrophoresis, 0.5x is acceptable as well. Higher concentrations will result in poor results due to excessive heat generation.
See also
- LB buffer, lithium borate buffer, a similar buffer containing lithium ions in place of Tris
- TAE buffer, a similar buffer containing acetic acid in place of boric acid