[Histonet] Re: in situ hybridization (bouin's fix)

[John A. Kiernan]

That's right. Picric acid removes some of the
bases from DNA, exposing deoxyribose units, which
can react as aldehydes. It's not a full-blown
Feulgen hydrolysis, but it's going that way.
Hybridization histochemistry requires the purine
and pyrimidine bases of the DNA in the tissue to
be all present and correct, to pair with those of
the probe. If you're using in situ hybridization
to detect messenger RNA, then Bouin's may well be
even more destructive because acid hydrolysis
breaks RNA into soluble fragments. 

John Kiernan
Anatomy, UWO
London, Canada
------------------------------
"Johnson, Teri" wrote:
> 
> Carlos,
> 
> I have not performed ISH on Bouin's fixed samples yet.  Frankly, I think
> it's a good idea to stay away from Bouins because of the acetic acid in
> the fixative. Most ISH protocols warn against using acid decalcifiers on
> samples slated for ISH.  If that is all you have to work with, I would
> use a standard ISH protocol and make no modifications and see if you get
> any result.  Make sure you use sense and anti-sense probe and compare
> the two.  Make sure you use a sample known to be positive for your
> target of interest.
> 
> Are you using DNA or RNA probes, and is your target cellular DNA,
> cellular RNA, or viral?
> 
> Teri Johnson, HT(ASCP)QIHC
> Managing Director Histology Facility
> Stowers Institute for Medical Research
> 1000 E. 50th St.
> Kansas City, MO 64133
>