Why NaCl is in so many buffers? - (Jan/07/2007 )
It seems that almost every single buffer i make has NaCl in it. It seems like a very basic question, but I dont know the answer.... why?
Because salt is a major component of all living systems. This is likely because of the prevalence of salt in the ocean. Biochemical buffers typically mimic the in vivo conditions, and these include salt.
in addition to phage 434, some enzymes, channels, receptors, transporters etc. need the ionic strength of Na+ and Cl-; also, NaCl is cheap
NaCl is most often used just to adjust ionic strength and/or osmolality of the buffer solutions. In some cases it may serve additional purposes as listed by earlier posters.