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I need help with an electrophoresis buffer pH problem!

Question asked by Heather Lander on Jun 24, 2013
Latest reply on Oct 31, 2013 by Peter Hsieh

Hi! My lab is trying to get a relatively new tissue electrophoresis system up and running. We are using the protocol provided by the lab that originally published the technique in Nature of this year. It's a technique called CLARITY. We have followed the instructions and for some reason, when we begin the electrophoresis, the pH of the buffer begins to drop and continues to drop significantly over the course of the electrophoresis, which takes several days.


So my question is, what are we doing wrong? Is there some detail that was left out of the protocol or is it simply a matter of how we are preparing the solution? Let me give you some more information that might help you understand what we are dealing with.


The electrophoresis buffer is: 200mM boric acid, 4% SDS, made in 10 Liter batches and pH'd to 8.5 using sodium hydroxide


Electrophoresis is carried out at 40V for 5 days


Can anyone tell me why the pH of our solution is dropping under these conditions or what I might be able to do to fix it? Could I add more sodium hydroxide everyday to re-pH it?


I've attached the protocol in case that might help.