Dina-

Are these by any chance fixed in 4% paraformaldehyde? If so, Yuck. Just
kidding, but I have also had this problem. The brains come out looking like
wads of wet tissue paper. My first recommendation would be to try to avoid
the paraform fix/paraffin combo. If you can, substitute another fix such as
good old 10% formalin or any other fix appropriate for your protocol. If you
are stuck with 4% paraformaldehyde( as many researchers insist upon it) make
certain you do a lengthy fix -a couple of days. I would slice the brain
before fixing into apx. 3mm slices. Since this is a neonate, I would give
another day in 70% EtOH before processing. I know some people like to use an
ethanol substitute for their paraformaldehyde-fixed brains. Anatech produces
Pro-Soft Dehydrant.

Good Luck!

Lorraine Gibbs
Physiology & Biophysics
University of Washington
----- Original Message -----
From: <dgaupp@tulane.edu>
To: <histonet@pathology.swmed.edu>
Sent: Thursday, April 26, 2001 8:45 AM
Subject: wrinkles in brain tissue(paraffin embedded)


> Dear histonetters,
>
> I have been having a problem with wrinkles in mice brain(approximately 30
days
> old).  The tissue don't look wrinkled when I cut it, but when I lay the
tissue
> in the water bath, it wrinkles all along the edges.  I have changed angles
on
> microtome, changed disposable blades several times, even changed water
bath
> (tried with & without gelatin).  Should I change my water bath temp?
Right now
> I have it at 42 degree Centigrade. Several days ago, I cut mice brain
without
> any problems.
>
> Any help is greatly appreciated.
>
> Thank you,
>
> Dina
> dgaupp@tulane.edu
>