RNase contamination and yellow MOPS?!?

Susanne Rohrer srohrer at immv.unizh.ch
Fri Mar 31 04:36:26 EST 2000

> ? On 21 Mar 2000, Wolfgang Schechinger wrote:
> ? RNAses remain fully active after autoclaving. And adding
> ? DEPC won't help either, because the RNAses in the autoclave (for instance
> ? from LB) may well diffuse into your bottle.

Let's not get paranoid. I can tell you our story to calm you down:

When I did my first northern blot, I took lots of care and made all my reagents
up with DEPC. A couple of fine blots later, we discovered that what one lab
member bought as DEPC was Diethyl phosphocyanate, abbreviated as DEPC in the
Sigma catalogue.  Diethyl Pyrocarbonate is abbreviated as DEP. So all the time we
had been working with "non-RNAse free" reagents, but our blots were fine (apart
from that our "fake" DEPC had messed around with the pH of our reagents).
The bottom line is,  If your reagents are sterile then you'll be fine, except if
milligram amounts or Rnase are flying around your lab.  One thing that did happen
to me on a test gel: I used Blue juice made up with glycerol that had been
sitting in my fridge for a while, and probably something had grown in it. No RNA
left at all. I switched to Ficoll.
but definitely the Rnases from your media will not sneak back into the bottles in
the autoclave!

No one got poisoned from the DEPC stuff - does anyone know how it is used
(peptide synthesis according to Sigma); is it harmful?


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