[Histonet] Bouin's rinsing protocol

gayle callis gayle.callis <@t> bresnan.net
Mon Feb 2 16:22:45 CST 2009

Geoff is correct on this, and even after rinsing, whether with 50% or 70%
alcohol for a long time, we were never able to totally remove the picric
acid prior to processing. The only way we successfully removed the picric
acid was after sections were deparaffinized and rehydrated.  At that point
we rinsed sections with running tap water until the picric acid e.g. yellow
color was totally removed. The old way learned years ago, was to rinse for
10 minutes before proceeding to staining, however we found the picric acid
rinsed away in less time, and did this by examining sections with naked eye.

This has been posted on Histonet many times over the years, so be sure and
do a search in Archives. Some people use saturated lithium carbonate in 70%
alcohol for picric acid removal.   

Just curious, are all your tissues fixed in Bouins, or just some special
tissue samples?  The only time we use Bouins anymore is to fix the
occasional testis or eye.  However, Davidson's has replaced Bouins for eyes
to avoid having to deal with picric acid which seems to eventually turn
everything it touches yellow.  We were very careful with big studies and
large volumes of tissues fixed in Bouins to change the first alcohols (70%,
80%, and 95%) daily after Bouins fixed tissue was processed in our VIP.    

Gayle M. Callis
Bozeman MT 

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Geoff
Sent: Monday, February 02, 2009 2:27 PM
To: Jennifer Anderson
Cc: histonet <@t> lists.utsouthwestern.edu
Subject: Re: [Histonet] Bouin's rinsing protocol

I was taught 4 changes of 50% EtOH, 1-1.5 hours each. The goal is to get 
most of the picrates out of the tissue for long-term storage (of blocks)
I don't know if one can ever get all of the yellow color out.


Jennifer Anderson wrote:
> Hello.
> I am looking for information regarding procedures for tissue handling
> after Bouin's fixation, prior to processing in a standard automated
> tissue processor (VIP).  We are handling pig, mouse, rat, and human
> samples, and will fix in Bouin's for 48-72 hrs.  I've been told to rinse
> until all yellow is washed out, and people generally rinse in 70%
> alcohol or water.  Sometimes it take days to wash all of the picric acid
> out.
> Thank you so much for your wealth of information!
> Jennifer M. Anderson, Scientist
> Halozyme Therapeutics, Inc.
> 11404 Sorrento Valley Road
> San Diego, CA 92121
> 858-704-8333
> janderson <@t> halozyme.com
> _______________________________________________
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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 
mcauliff <@t> umdnj.edu

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