[Histonet] procedure for osmium and potassium chromate?

[Amos Brooks]

Hi,
     Yes, of course it's dangerous. (OK, granted really dangerous) Histology
cannot be done with distilled water alone. Risks are part of the job.
Knowledge of the risks and understanding of how to minimize these risks is
what makes it possible to do our jobs and not have serious problems.
     Of course if there is another way of doing something without the
hazardous chemicals while still getting the same results, one would be a
complete idiot not to use the safer alternative. (This is why we cannot find
mercury in hematoxylin formulations anymore same results, safer chemicals)
There are some things that cannot be substituted. I have looked but I have
not find any way of demonstrating lipids, fats or oils in paraffin sections.
(If anyone knows of one please enlighten me!) Sometimes paraffin sections
are needed instead of frozen sections. This is one that works. So use of the
chemical (under obvious precautions) is justifiable.
     So because I'm a devil's advocate, the reference can be found in
Gretchen Humanson's Animal Tissue Techniques. However the fair warnings
given earlier are very right. Reading the MSDS is a must. Also for an
interesting read check out the Wikipedia pages:
http://en.wikipedia.org/wiki/Osmium_tetroxide
http://en.wikipedia.org/wiki/Potassium_dichromate

Ok I'm getting off the soapbox before someone kicks it out from under me :-)
Amos


Message: 11
Date: Wed, 2 Dec 2009 13:15:03 -0800 (PST)
From: Rene J Buesa <rjbuesa <@t> yahoo.com>
Subject: Re: [Histonet] procedure for osmium and potassium chromate?
To: histonet <@t> pathology.swmed.edu, Liz Chlipala <liz <@t> premierlab.com>
Message-ID: <405109.33036.qm <@t> web65705.mail.ac4.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

I really would suggest you to find an alternative procedure.
Osmium tetroxyde is EXTREMELY dangerous and has to be used under extreme
precautions.
I don't think the results are worth the effort given the great dangers it
poses.
I for one would not share the procedure with you.
René J.

--- On Wed, 12/2/09, Liz Chlipala <liz <@t> premierlab.com> wrote:
From: Liz Chlipala <liz <@t> premierlab.com>
Subject: [Histonet] procedure for osmium and potassium chromate?
To: histonet <@t> pathology.swmed.edu
Date: Wednesday, December 2, 2009, 3:13 PM

I'm trying to find a procedure for staining fat in tissues with osmium
and I think potassium dichromate, does anyone out there have this
protocol available.  I have found it before on the web but for some
reason I can't  find it this time.

Liz