[Histonet] Need a chemist's opinion on formalin fixation reversal

Andrea T. Hooper anh2006 <@t> med.cornell.edu
Mon Jun 6 16:54:27 CDT 2005

Can one of the chemists on board please address the issue of washing 
to reverse formalin fixation? (sorry if you have done so already but 
I must have missed it).

This is a new concept to me and makes me very very nervous about some 
of my routines in the lab as often times I can only occasionally 
process and have samples in the fridge for sometime after fixation 
yet before processing ... yikes!

Thank you thank you!

>I have been asked to elaborate on my reference to washing tissues to reverse
>the effects of formalin fixation iliminating the possible need for AR.
>Here goes:
>I found the reference to Washing in a book called Introduction to
>Immunocytochemistry 3rd Edition  J.M. Polak and S. Van Noorden pg. 24- 3.8.2
>"The simplest form of reversing the effects of formalin is to wash the
>tissue well before processing, but this is not usually possible in
>histopathology laboratories, where rapid turnowver of specimens is
>I have not tested this extensively but have done a little, especially on
>over fixed samples, the data is yet to be confirmed but I am looking into it
>as we speak.  I will keep you all posted.


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