Hi
I like to know which buffer should be used for the preparation of low pH solution in order to activate TRPV1 channel (capsaicin sensitive VR1 channel). In general, people seem to use MES, while MES can be suitable for the pH range of the lowest 5.5. For lower pH value than 5.5, what is the suitable buffer?
Thanks for your information.

You'll find a table of most of the biological buffers you will ever need to use for your applications and the ranges for which they are suitable here.

http://www.sigmaaldrich.com/Brands/Fluka___Riedel_Home/Bioscience/BioChemika_Ultra/Biological_Buffers.html#sortedbybufferrange