RNAses

[Tracy Aquilla]

In Article <3gpjgi$923 at netnews.upenn.edu>, aaron at netnews.upenn.edu (Aaron
Pawlyk) wrote:
>Kusol Pootanakit (pootanak at hermws.bc.edu) wrote:
>: Hi,
>
>: Just out of curiosity, does anyone out there know if after one cross-linked
>: RNA on to nylon membrane; can the RNases still get to them.
>
>: thanks
>
>If the RNA is well cross-linked RNases won't have as much of an effect on them
>as they will in solution.  The RNA cross-links on its backbone to the membrane
>and it will be more difficult for the RNAse to cleave the bonds.  Also, with
>the backbone attached the the membrane, it does not make as much of a
>difference if the RNA is cleaved; it will still be held into place by the 
>cross-linking.
>
>But avoid RNAses anyways.  
>
>                        -- Aaron
>

I have found from experience that RNAses can ruin a Northern blot very
rapidly. You can do an experiment to test this hypothesis. Hybridize a good
blot in the presence of RNAse (using a DNA probe). Before RNAse and after
treatment there will be a BIG difference in the signal obtained.
    Tracy