pH for RNA work

Bernard Murray bernard at
Mon Feb 3 23:56:00 EST 1997

In article <v01530501af1be322547d@[]>, jmorlan at SFSU.EDU says...
>We rinse our electrode in DEPC-treated water.  Strictly speaking, this does
>not make the electrode RNAse free, but we seldom have any problems doing it
>this way.

>>While making RNAse free Tris, does the pH electrode have to be
>>RNase free for adjusting the pH? If yes, then how do you make an
>>electrode RNase free?
>>Thanks in advance

I'm a little more paranoid and go through the following cycle;

a) carefully remove a small aliquot from the main solution
b) check the pH
c) try and adjust the pH of the main solution

until the pH of the solution is correct.  You can start out with
testing single drops on pH paper until you are within 1 pH unit.
I fully admit this may be a little over the top but the pH meter
is shared with a lot of people (and I don't trust any of them). least I have yet to start DEPC treating my NaOH and HCl stocks ;-)


Bernard Murray, Ph.D.
bernard at (National Cancer Institute, NIH, Bethesda MD, USA)

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