Difference between HEPES and HEPES sodium salt ? - (Dec/05/2016 )

Hi

What is the difference between HEPES and HEPES sodium salt ? Can I substitute one for the other while making HEPES buffer ?

Thanks

hepes may be the free acid whereas the sodium salt is neutralized.

either or both can be used to prepare buffers, just make sure you take into account formula weight differences when calculating concentration.