I found the following recipe at Abcam and converted it to 5x to make a stock solution.

Running buffer (Tris-Glycine/SDS)

• 25 mM Tris base
• 190 mM glycine
• 0.1% SDS
• Check the pH and adjust to 8.3

for 1 liter at 5x:

15.1 grams Tris base

71.3 grams glycine

~800 mL Milli-Q water, check that pH = 8.3

add 5 mL 20% SDS

qs 1000 mL Milli-q water

When I mixed the Tris and glycine as above, the pH was about 8.9. I started over usinig only 12 g of Tris base and the pH was still too high. I checked with another pH meter (both of which showed correct pH with standard pH 7 buffer) and got the same result.

What the heck? Did I have a brain tumor for breakfast? Can anyone see an error in my calculations?

My understanding was that you are not really supposed to adjust the pH of this buffer to avoid creating salt. I expected it to come out pretty much at the desired pH if using the right ratio of Tris to glycine.