It's the water. was Re: DEPC Vs DMPC

Nick Theodorakis nicholas_theodorakis at
Tue Oct 17 12:11:57 EST 2000

In article <BJi+nIA6VG75EA1N at>,
  "Dr. Duncan Clark" <Duncan at> wrote:
> In article <8shmj5$jpl$1 at>, the eminent Nick Theodorakis
> at - Before you buy. wrote
> >In article <39EBED1E.97E783C3 at>,
> >  Paul Cullen <Paul.Cullen at> wrote:
> >> I have been using DMPC to rid my solutions of RNases.
> >...
> >
> >Here's my $0.02: I haven't used DEPC (or DMPC) for years. Use good water.
> >Pure water is RNAse free. And my RNA is just fine.
> I agree, but not every lab has the funds to change their water system to
> something more modern etc.

Ok, but if your water has RNase, then what else might it have?
Proteases? Trace metals? Dioxins? Aromatic hydrocarbons? Endotoxin? There
are a lot of ways to mess up your experiment besides having RNase in it,
and many of those are much more subtle and harder to detect and rectify.
I think your better off knowing your water is water, and not mostly water
with trace impurites and carbonate and ethanol (from DEPC).

Here is an anecdote: when I was in grad. school, an investigator whose
lab was in another building had to come into our lab to make his phage
packaging extract (I'm dating myself here) because his extracts made in
his own lab wouldn't work. Sure, he could DEPC his RNAse away, but there
was something more subtly wrong with his water supply that would kill his
packaging extract.

Nick Theodorakis
nicholas_theodorakis at

Sent via
Before you buy.

More information about the Methods mailing list