Dear Beth

> We just completed a study consisting of mouse fat.  This fat was taken
> from around such tissues as the uterus, heart, etc.  We used a cryostat
> made by Microm and had it set at everywhere from -18 to -35 degrees.  We
> left the tissue in the cryostat overnight and still no luck.  We could
> not get a section no matter how thick or thin we tried cutting them.  We
> then tried Histofreeze, still no luck.  To make a long story short, we
> ended up giving "fat smears".  We have never had problems with our
> cryostat and the techs that were working on this project had over a
> century of experience with frozens.  Maybe Instrumedics could have come
> to the rescue!

I am not surprised. Fat just will not freeze under the conditions 
available in most Histo labs. If the tissue will not freeze, you 
can't cryosection it. 
When cutting urgent frozen sections, I would always ask the 
pathologist to dissect as much of the fat as possible. Is the 
diagnosis resting in the fat or is it in the solid mass that it 
surrounds? Sections have always been easier to cut and of  better 
quality.
So my recommendation: cryotomy is not the preferred method for the 
examination of fat.

Regards, Tony
.
Tony Henwood
Senior Scientist
Anatomical Pathology
Royal Prince Alfred Hospital
Sydney, AUSTRALIA

http://www2.one.net.au/~henwood
http://www.pathsearch.com/homepages/TonyHenwood/default.html