RNA folklore?

[Cornelius Krasel]

hrasal at marc.cri.nz wrote:
> There are two things that  I'm curious about.  When I first started 
> working with RNA, I was told that autoclaving inactivated RNAses, but the 
> RNAse protein will (after a certain period, 24 hours or so), reform into the 
> active enzyme.  I had assumed that this was stated in Stryers Biochemistry.
> I was wrong.  Actually, it was denaturation of ribonuclease in 6M guanidine
> HCl followed by removal of the guanidine by dialysis.  So, is reactivation
> of RNAse activity after autoclaving an urban legend, or is it real?

I don't know about autoclaving but to get DNase-free RNase you make a
solution of cheap RNase A (which contains DNase) and boil it for a while.
When cooling down, the RNase will renature, the DNase will not. For
details see Maniatis.

--Cornelius.

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