Checking pH of RNase Free Solutions - (Nov/19/2012 )

Trying to prepare reagents for Denaturing RNA gel. Is it possible for the pH probe or storage buffer to be contaminated with RNase? Can the probe be rinsed with DEPC treated water or should I take an aliquot of the solution and use pH paper to check the pH. I was wondering how I can check the pH of RNase free solution without contaminating it with RNase?

Yes, it is possible for the probe to be contaminated with RNase, and rinsing it with DEPC treated water will not get rid of the RNases as the DEPC is by this time CO2 and H2O. You need to take an aliquot and measure the pH in that with the probe if possible, pH paper isn't all that accurate; then throw the aliquot out, ...repeat until desired pH is reached.