Molecular biologists often use tris-based conduction buffers like TBE or TAE in running DNA gels. These buffers are known to overheat at high voltages, causing problems with gel integrity, sample denaturation and more. The voltage thus needs to be limited to a maximum of 5-10 volts/cm (e.g 100 volts for a 10 cm gel) leading to extended running time, sometimes to hours.
With 10mM Sodium Tetraborate (CAS#: 1330-43-4, Na2B4O7, Borax), the voltage can be increased to 35 volts/cm without any problem, reducing the time taken to run gels by up to 7 times for standard applications (e.g. separation of DNA fragments from 100 bp - 5 kbp).
Our lab’s standard DNA gel buffer has become 20 g of Borax into 1 l of water which gives a 20x stock solution. Small gels run in 10-15 minutes at 200V.
Preparation of gel electrophoresis buffer for separation of DNA fragments from 100 bp - 5 kbp