Hi there,

Although I am not experienced with breast tissue, we are dealing with
similar "fatty problems" when handling atheresclerotic tissue specimens.
When microwaving a formalin-fixed atherosclerotic tissue specimen the fatty
plaque is sometimes gone as well as parts of the adventitia. The media
stays nicely on the slide (unfortunately this is the most uninteresting
part of tissue to us).

I would like to bring in another fixative maybe worthwhile to test: methacarn.
It is composed of 6 parts methanol, 3 parts chloroform and 1 part acetic
acid. Our Japanese collaboratorsin Osaka who came up with it even store
whole hearts in methacarn!! When replacing methanol by alcohol it is named
"Carnoy". I am not aware of any differences between methacarn and Carnoy.
Since no formalin is involved, methacarn is a non-crosslinking fixative.
Therefore, you do not need to microwave for immuno's. In our hands
immunostaining (surfcace, cellular and nuclear markers) after
methacarn-fixation is even somewhat stronger than after
formalin-fixation/microwave treatment!!

Have a happy staining-day using methacarn!!

Chris van der Loos
Dept of Cardiovascular Pathology
Academical Medical Centre
Amsterdam, The Netherlands