I am with Wayne on this one. While I have not tried to make it explode
it does seem to me that the dangers are hyped beyond reason.
Years ago an old bottle of picric acid would be discovered in a high
school chemistry lab. Horrors! Call the bomb squad! So it was taken out
to a large field, packed
with explosives and BOOM! Of course it exploded, it was surrounded with
explosives.
Geoff
On 9/14/2012 8:58 PM, E. Wayne Johnson wrote:
What danger of Picric Acid are you concerned with?
Surely its not the hyped explosion hazards.
We use picric acid and as inquisitive boys we have tried very hard to
ignite it thinking it would be fun.
We dried some down and wrapped it in aluminum foil and with
appropriate protection outdoors beat it with a hammer.
So very disappointing. We only made it flat.
We tried heating some. It does burn pretty good but not really
dramatically.
We tried purifying and recrystallizing it and it still didnt do
anything spectacular.
Our conclusion that as fireworks, pure picric acid is pretty much a dud.
I have done some reading about picric acid and it seems that in lab
conditions a
picric acid explosion is very unlikely maybe impossible even if the
stuff is very dry indeed.
We do keep our picric acid wet in a safe spot for storage.
Some metal salts of picric acid are said to be much more sensitive.
We havent made any lead picrate to play with
since we are worried about aerosolizing the lead when it does explode
or flash.
There are some youtube movies about how to make explosive derivatives
of picric acid. it seems
that picric acid is just not a very good explosive, and that small
amounts in free open air are unlikely to explode.
I have been unable to find any reference to any lab accidents with
picric acid.
Does anyone have any information to the contrary?
On 9/15/2012 7:55 AM, Jackie O'Connor wrote:
As a GLP tox lab, we have done away with using Bouin's altogether -
there is literature out there (somewhere - not handy now) that
indicates Modified Davidson's fixative provides the same testicular
detail of bouins, without the picric acid danger. We switched about
3-4 years ago, and our testicle experts are happy. I believe most
labs are getting away from Bouins.
Jackie O'
-----Original Message-----
From: Frances Elizabeth Barron<[email protected]>
To: histonet<[email protected]>
Sent: Fri, Sep 14, 2012 12:21 pm
Subject: [Histonet] RE: mouse testis in Bouins
Hi Margaret,
Our protocol for whole mouse embryos E14.5-E18.5 was to fix in
Bouin's for 5-7
days at room temp (I have gone longer, but it isn't exactly
recommended). Most
of the length of time, however, was to compensate for the large
tissue size and
need for good penetration. I'm not sure how that converts to your
particular
tissue of interest.
For long term storage, John Shelton at UT Southwestern (who did our
vacuum
processing for large embryos) told me that it was preferred to put
them in 1%
neutral buffered formalin and store them at room temp. We had
previously been
storing them in 70% EtOH, but John said that the long exposure to
EtOH leads to
excessive drying of the tissue and ultimately brittleness if used
later. I'm
assuming this thought could be applied to any tissue piece, but I
don't have
enough experience to really know. We have successfully gotten
beautiful paraffin
sections from 3mo-1year samples that have been stored this way.
I'm hoping this will be of some help to you, and perhaps others in
the list can
comment.
Best of luck,
~Francie
*******************************************************
Francie Barron, Ph.D.
Postdoctoral Fellow, Joseph Wu Lab
Stanford University School of Medicine
Lorry I. Lokey Stem Cell Research Building
265 Campus Drive, Room G1105
Stanford, CA 94305-5454
Phone: (650) 724-5564 or (650) 724-9240
Fax: (650) 736-0234
*******************************************************
Message: 7
Date: Fri, 14 Sep 2012 10:06:33 -0300
From: "Margaret Horne"<[email protected]>
Subject: [Histonet] mouse testis in Bouins
To:<[email protected]>
Message-ID:<[email protected]>
Content-Type: text/plain; charset="us-ascii"
Hello Everyone, I am asking this for a friend.
How long can mouse testis be kept in Bouins without distortion of cell
morphology? Days? weeks? months? years?
I noticed in the Archives that many people fix in Bouins , rinse, then
store in 70% EtOH. This is preferable I assume. Again, how long is ok?
Thanks in advance for the sharing of your accumulated wisdom,
Margaret
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--
--
**********************************************
Geoff McAuliffe, Ph.D.
Neuroscience and Cell Biology
Robert Wood Johnson Medical School
675 Hoes Lane, Piscataway, NJ 08854
voice: (732)-235-4583; fax: -4029
[email protected]
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