X-Message-Number: 6027 Date: Thu, 4 Apr 1996 21:28:10 -0800 (PST) From: Doug Skrecky <> Subject: brain freeze-drying as an economical alternative (erratum) ******Appologies***** (I guess I was a little too excited when I originally posted this message. It contained a rather glaring math error, which was due to my mixing up freeze-dry data between brain slices with an intact brain. The corrected message is below.) Freeze-drying a brain should reduce storage costs quite significantly since liquid nitrogen cryostats would no longer be needed for storage. How much would it cost to freeze-dry a brain? Probably not very much as the following information shows. In his book "Freeze-Drying Biological Specimens: A Laboratory Manual" Rolland O. Hower from the Smithsonian Institution details his experiences in freeze-drying a wide variety of biological specimens. Freeze-drying of a formalin fixed 1386 gram human brain took just 28 days at -30 C. Weight loss was 1145 grams or 83%. Slicing the brain reduced drying time to 14 days. Increasing the storage temperature to -5 C reduced drying time of an intact brain to 7 days, though numerous cracks were evident. Considering its size the human brain seems to be remarkablely quick and easy to freeze-dry. A barred owl weighing 1369 grams took 130 days to freeze-dry at -20 C. A tortoise took 132 days, while an alligator took 9 months at -20 C. The absence of either a thick epidermis or bone which can act as vapour barriers may be the reason why the human brain was so quick to dry. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=6027