Preparing Borax RapidBuffer for electrophoresis
Stephane Fadanka, Nadine Mowoh, Jenny Molloy, Cordellia Fulai
Abstract
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.
SCOPE:
Preparation of gel electrophoresis buffer for separation of DNA fragments from 100 bp - 5 kbp
Steps
Preparing
Weigh out a certain amount of borate and place into a vacuum Tupperware half filled with silica beads.
place the lid on top and cover tightly, then use the vacuum pump to extract air inside and allow to dry for12h 0m 0s at 37°C).
1.2 Carefully pour it out into zip lock bags and seal to avoid it from absorbing moisture and store in cool dry place.
Preparation of 10x Borax RapidBuffer Solution
Use a spatula to measure out and weigh 10g of Borax (Sodium Tetraborate, CAS#: 1330-43-4)
Pour powder into a graduated 1000mL glass beaker or flask
Using a 1000mL measuring cylinder, measure800mL of distilled or deionised water and add to the 1000mL beaker.
Add a magnetic flea and use a magnetic stirrer at Room temperature to fully dissolve the borax powder.
Add distilled or de-ionised water to a total of 1000mL and stir again for 0h 3m 0s
Pour the prepared solution into a clean, labelled screw-top 1000mL glass or plastic storage bottle and store at Room temperature until use.
Preparation of 1x Borax RapidBuffer Solution (500ml)
Use a 100mL measuring cylinder to measure out 50mLof 10X RapidBuffer into a 500mL graduated beaker or flask.
Add approx 450mL distilled or deionised water, sufficient to make up the volume to 500mL
1X RapidBuffer solution is now ready for use and can be stored at Room temperature for use within one month.
