tion medications. First, catch your snail. This is the easy part. Now place the snail in the container, top it off with water, and put it in your freezer. Wait just long enough for the water to turn to ice (an hour should be sufficient). Quickly remove the container and run it under warm water. As the ice melts, transfer your snail to a smooth surface such as a dinner plate, and continue the warm-water treatment.

When the snail recovers its senses, it should start
crawling away at a fast pace (relatively speaking). If
SAFELY FREEZING your snail turns yellow and breaks in half, you left it
AND THAWING AN ORGAN in the freezer too long. Even snails become injured
Human organs represent a bigger challenge when they are 100% frozen without protection from
because their intricate, delicate structure is ice damage.
easily disrupted by ice crystallization. Luyet man- Those who want to take cryobiology more seri-
aged to revive some fragments of rat hearts, but ously can obtain some glycerol from a chemical
never recovered a whole organ from a very low supply company. (Glycerol is nonhazardous as long
temperature. That achievement eluded scientists as you refrain from drinking it.) If you have access
until 2005, when a team led by cryobiologist to a cheap microscope, you can replicate British
Gregory Fahy successfully reimplanted a rabbit research from the 1950s by soaking sperm or blood
kidney after it had been preserved at - 130°C. Dr. Fahy cells in various concentrations of glycerol. Subject
spent a large part of his professional life perfecting your samples to liquid nitrogen, then rewarm them
the cryoprotectant that enabled this feat, which and see if the cells resume their activity.
requires a well-equipped laboratory. Still, Fahy If you’re feeling even more ambitious, you can
points out that backyard cryobiologists can still perform the same procedure with nematode worms,
replicate the very simple demos that Basile Luyet which are as small as tardigrades but more readily
ran more than 50 years ago. available. In fact, your backyard may be crawling
The simplest one doesn’t even require glycerol. with them. You can also buy them by mail order from
“I’ve been told that Luyet would toss two goldfish ecologically enlightened companies that sell them as
into some liquid nitrogen,” Fahy says. “He would a natural pest control, since the microscopic worms
quickly withdraw Goldfish A, which would seem stiff eat fly larvae. Reviving a nematode from a period in
and frozen — but it would resume wriggling after it liquid nitrogen is a challenge, but it can be done.
was placed in warm water.” Basile Luyet never achieved his ambition to stop
Luyet would then startle onlookers by removing and start life processes on a large scale, but his basic
Goldfish B and snapping it in half. This may not have studies had serious long-term implications.
been a completely fair demonstration, since Goldfish Clearly, a surgical patient who reawakens after
B was exposed to liquid nitrogen a little longer than zero brain activity at a low temperature has not
Goldfish A. It’s not clear whether Luyet realized that, been dead in the usual meaning of the term. By the
to some extent, he had rigged his experiment, but at same logic, a frozen blood cell, or a cryopreserved
the very least it remains a unique ... icebreaker? nematode, is not dead either. If we can revive a rabbit

Liquid nitrogen is available in most urban areas kidney, or (eventually) a whole animal, by preserving (search online for “liquid gases”), and it is generally it in such a way that its cells remain viable, we may inexpensive. It is nontoxic, but must be handled with begin to challenge the conventional concept of death caution, since its temperature of -196°C can cause to the point where it becomes virtually meaningless. serious injury to any exposed human tissue. Always wear heavy gloves and eye protection!

antifreeze, to replace cellular water and reduce the volume of ice. They described the glycerol as a “cryoprotectant” and named their new field of research “cryobiology,” from the Greek word “kryos,” meaning “cold.” Today, glycerol is routinely used to protect sperm and ova that are preserved in liquid nitrogen. Countless babies have been born from human germ plasm that has endured long periods of lifeless storage with this method.

 

PUTTING A SNAIL INTO SUSPENDED ANIMATION If you live in a part of the world where snails are abundant, Fahy suggests another simple experiment, which he performed himself as a high school student. All you need is a domestic freezer and a thin-walled vial, such as the kind used for prescrip-

FURTHER READING

societyforcryobiology.org
21cm.com
alcor.org

Charles Platt has been a senior writer for Wired and has written science fiction novels such as The Silicon Man.