性能描述

MES is one of a number of so-called Good buffers
developed for biological applications, with the criteria:
midrange pKa, maximum water solubility and minimum
solubility in all other solvents, minimal salt effects,
minimal change in pK with temperature, chemically and
enzymatically stable, minimal absorption in visible or
UV spectral range and easily synthesized.
A buffer using MES can be prepared by titrating with
NaOH to the desired pH. Alternatively, stock solutions
of MES and MES sodium salt can be mixed to attain the
desired pH. Standard mixing tables using stock
solutions to prepare buffers of a given pH have been
published.3 MES is not recommended for buffering at
pH 7.4; other buffers should be considered.1
Precautions and Disclaimer
These products are for R&D use only, not for drug,
household, or other uses. Please consult the Material
Safety Data Sheet for information regarding hazards
and safe handling practices.
Preparation Instructions
MES is soluble in water, giving a clear colorless
solution at concentrations of 0.5 M or higher. (M 8250 is
tested at 20 g/80 mL water, or approximately 1.3 M.)4
The pH of a solution should be between 2.5 and 5,
depending on concentration. A saturated solution at
0 °C is approximately 0.65 M.1
Storage/Stability
Solutions are stable at 2-8 °C for months. Sterilize by
filtration through 0.2 mm filters. Autoclaving is not
recommended for any sulfonic acid buffer. If buffers
must be nuclease-free, treat the water first, then add
the buffer after autoclaving. When MES solutions are
autoclaved, they turn yellow (although pH does not
change measurably). The identity of the yellow
breakdown product is unknown.
References
1. Good, Norman E. et al., Biochemistry, 5, 467-477
(1966).
2. Methods in Enzymology, 182, 24-38 (1990).
3. Data for Biochemical Research, 3rd Ed., eds.
Dawson, R.M.C. et al., (Oxford Press, 1987), p.
410, 424, 431.