[Histonet] RE: mouse testis in Bouins/Picric acid hazzards

[Geoff]

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<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
>>
>
>
> _______________________________________________
> Histonet mailing list
> Histonet <@t> lists.utsouthwestern.edu
> http://lists.utsouthwestern.edu/mailman/listinfo/histonet


-- 
--
**********************************************
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
mcauliff <@t> umdnj.edu
**********************************************