The Loh Down On Science

Sure, you can freeze a frog, but can you thaw it?

Andrew Rosendale/JEB

Outside of a science fiction movie, can the frozen . . . come back to life?

This is Sandra Tsing Loh with the Loh Down on Science, saying:

Yes . . . if you’re an Arctic frog.

Meet Jon Costanzo and Richard Lee of Miami University in Ohio. They wondered about a species of wood frog that ranges from the southeastern U.S. all the way to the Arctic Circle. These hardy amphibians can survive for weeks with most of their body water frozen.  But how?

To find out, the duo had their students collect specimens in Ohio and Alaska.  Then, back in the lab, they experimentally froze and thawed the froggies.  Result?  Northern frogs could be frozen to much lower temperatures than their Midwest cousins and still be revived safely!  

Why the difference?  Probably higher concentrations of cryoprotectants in the Alaskan frogs.  These are chemicals like glucose and urea, and possibly others, that lower the freezing point of the frogs’ tissues, protecting their cells from damage.

Natural antifreeze may be fine for wood frogs . . . but for the rest of us, a down parka still works better.  And some hot chocolate.


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