A friend wishes to prepare a 1M solution of PIPES (buffer) at pH 6.4. He needs it for working with RNA. Questions: 1. What should be used for its titration?, NaOH / KOH or else? 2. Can PIPES be autoclaved ? Should it be autoclaved at all .... any reason to think there would be RNAases there? 3. Can it be autoclaved in the presence of DEPC? Thanks in advance, Nir