Dear Histonetters,

We experienced an interesting problem when working with some muscle tissue
the other day and was wondering if anyone out there has experienced it and
if so how did they correct for it.

We frozen some muscle tissue in isopentane cooled in liquid nitrogen to a
temperature of -160. The tissue looked compeletly frozen when removed. We
immediately placed the tissue in a vial and put in the -80 freezer. We
embedded in OCT and tried to cut and all we got was a big hole in the OCT.
The tissue seemed as though it was not frozen. Any idea of what happened??
We have done this with other tissue and it worked fine. We know the freezer
did not thaw out. So we are at a loss. 

I would appreciate any input! Thanks in advance gang!
Lynn Gardner, HT(ASCP)