[Histonet] RE: mouse testis in Bouins

[E. Wayne Johnson]

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<fbarron <@t> stanford.edu>
> To: histonet<histonet <@t> lists.utsouthwestern.edu>
> 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"<Mhorne <@t> upei.ca>
> Subject: [Histonet] mouse testis in Bouins
> To:<histonet <@t> lists.utsouthwestern.edu>
> Message-ID:<505301A9020000D10001841D <@t> oes-grpwise.novell.upei.ca>
> 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
>
>
>
> _______________________________________________
> Histonet mailing list
> Histonet <@t> lists.utsouthwestern.edu
> http://lists.utsouthwestern.edu/mailman/listinfo/histonet
>
>
> _______________________________________________
> Histonet mailing list
> Histonet <@t> lists.utsouthwestern.edu
> http://lists.utsouthwestern.edu/mailman/listinfo/histonet
>
>