Stacking Tris Molarity.. - how much.. same as resolving? (Sep/04/2006 )

Hi all,

Have a very basic question..

We at the lab use 0.5 M Tris-Cl in the stacking pH 6.8 while 1.5 M Tris-Cl pH 8.8 in the resolving SDS-PAGE gels. the pH difference i do understand.. is there a reason behind the molarity difference that i m not aware of yet? Plz do let me know:)

Thanks!

you are looking at the concentration of the stock solutions. you need to look at the final concentration in the working solutions to see if there is really a difference in buffer concentration.

That is what I use too. I assume it is somthing to do with the fact that proteins move faster through the stacking gel.

i use same buffers, and a i use 2.5ml for 10ml finals in both resolving/stacking, the ratio between morarity stay equal, 1 to 3
I think that's the need to have a stronger control of pH during resolving part of the electrophoresis.