SB buffer

SB 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 Sodium borate buffer, usually at pH 8.0, and NaOH, which sequesters divalent cations. It has a lower conductivity, produces sharper bands, and can be run at higher speeds than can gels made from TBE buffer or TAE buffer (5–35 V/cm as compared to 5–10 V/cm). At a given voltage, the heat generation and thus the gel temperature is much lower than with TBE or TAE buffers, therefore the voltage can be increased to speed up electrophoresis so that a gel run takes only a fraction of the usual time. Downstream applications, such as isolation of DNA from a gel slice or southern blot analysis, work as expected with sodium borate gels.

Lithium borate is similar to sodium borate and has all of its advantages, but permits use of even higher voltages due to the lower conductivity of lithium ions as compared to sodium ions. However, lithium borate is much more expensive.

See also

• TBE buffer

External links

• Sodium borate as an electrophoresis buffer
• Cost-effective media for the rapid and high resolution of small DNA fragments using polyacrylamide-based electrophoresis
• Analysis of oligonucleotide annealing by electrophoresis in agarose gels using sodium borate conductive medium