Simply put in the microwave for few rounds, 25 seconds each. It will revert to crystal clear buffer. This work perfectly even when crystallization is heavy.

10x TBE must be stored at room temperature. Most likely that buffer precipitattion can be caused by storing at low temperatures because of high concentation of salts in buffer and chandging solubility of different salts.

Michelle,

I keep the TBE in a water bath at 50-60oC for an hour or so and keep mixing the solution from time to time. The precipitate usually dissolves and stays in the solution for a few weeks. Since you are using 5L packs, it might need more incubation time and also more heating-storage cycles.

Good luck!

Usually when we see a large amounts of precipitate, We just autoclave the buffer and its again ready to use.

The main problem with the precipitates seems to be dust, which acts as a source for forming crystals. Filtered solutions usually have a longer shelf life.

There is even a publication about this: Long-term storage of concentrated tris-borate-EDTA electrophoresis buffers without precipitation. Biotechniques. 1991 Feb;10(2):182.

Reheating, as indicated by others, usually does the trick. If not, I usually discard the TBE buffer. Precipitates, which stick to the walls of your bottle can be removed with diluted hydrochloric acid.

As already noted, TBA has high concentrations of salts that tend to form cristals as soon as something is present serving as cristallization origin. Hence, the solution always kind of forms a gradient with highest concentration at the bottom. Yes, heating is the best way to get the salts back into solution, but you also have to make sure that you ALWAYS mix the TBE thoroughly before you take an aliquot out. Else the concentration of the remaining solution starts to raise and you won't be able to completely resolubilize the salt again.

Thank you for all the answers. I will try to heat the container at 60°C for the week-end !!

a colleague of mine had precipitates in 20X TBE and solved the problem with autoclaving. TBE works fine now

Re-autoclave or, much quicker, give it a quick microwave. The precipitates will dissolve and the buffer should work just fine.

If you see precipitate you can re-autoclave or, much quicker, give it a quick microwave. The precipitates will dissolve and the buffer should work just fine.

I agree with all the suggestions but the problem is that the precipitate is already thick and sticks to the bottom of the plastic container and as I said, it will not withstand autoclave !! All the week-end at 60°C had almost no effect (but without mixing). The container is also too big to enter our microwave oven. I will try to pour into glass bottles or erlen to be able to autoclave or boil in the microwave. If this don't work, I will buy a new one and transfer into glass bottles, filter, and autoclave !!!!

Simply put in the microwave for few rounds, 25 seconds each. It will revert to crystal clear buffer. This work perfectly even when crystallization is heavy.

You can use a heating plate and constant stirring for about 4 hours

Microwave did work to break the large crystals into small particles that could be homogenized in the liquid when properly mixed. I can then use the 10X 'slurry' to prepare the 0.5X working solution, and another microwave gives me crystal clear working buffer! Thanks for sharing.