Dr. Mooney:
Try this before spraying the paraffin block with Histofreeze. Take a folded
Kim Wipe tissue that has been dipped in the waterbath and place it on the cut
face of the waterbath. The wet Kim Wipe will hydrate and soften the block and
it will act as an insulator to prevent cracking and crazing when you spray it
with Histofreeze. I keep two folded Kim Wipes, one on the edge of the
waterbath and the other on a metal part of the microtome. One cold and one
warm.
Regards,

Jim Burchette
Duke Immunopathology