John Thompson jrt at
Wed Aug 11 20:34:31 EST 1999

Nick Theodorakis <nicholas_theodorakis at> wrote:

>Since D(E/M)PC modifies nucleic acids as well, I would think that the
>greater instability of DMPC in water would be an advantage, since there
>would be a lesser chance that some would remain in solution when it came
>in contact with the RNA.
DEPC was used in chemical sequencing reactions where something like
10% DEPC and elevated temperature were required to get partial
reaction.  So I don't think 0.05% DEPC on ice really poses much of a
chemical modification problem for RNA.  DEPC-treated RNA is perfectly
fine for hybridization analysis. Nevertheless, I still avoid DEPC when
the downstream use is as a template of some kind. 

As a compromise one might consider adding DEPC at an early lysis stage
and after allowing a short time for it to react with RNAses, and a
molar excess of histidine to scavenge the remaining DEPC.

John Thompson

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