I have a quick question regarding flash freezing of rat brain in freezing isopentane. Does anyone have an opinion on flash-freezing by simply dropping the brain into the isopentane versus placing it in a container with OCT or similar media and then placing this into the isopentane? I have been running into problems with both micro and macro cracking of the tissue.

Thanks,
Margaret McKinney.

Margaret McKinney
Brown University Medical School
97 Waterman St.
Providence, RI 02912