Cryobiology

My dad had a buddy when I was growing up that swore up and down that if you took a live duck and put it in the freezer and froze it solid, you could then thaw it out and it would still be alive. I never tried it, so I can't say for sure if it would work or not, but I doubt it. Some animals can take very cold temperatures but the guy insisted that the duck could be frozen rock solid.

Then there are those companies that say they will freeze you so that some day science can figure out how to thaw you out and cure your ills and then bring you back to life? I wouldn't bother. Science has to figure out a safe way to do the freezing part before it's likely to work. The problem isn't in the thawing out, it's in the freezing.

When you take a few cells and start to freeze them, two different problems come up. First, if you are freezing them slowly, ice crystals form outside the cells. Ice is frozen water (I hope you knew that already) and so when it becomes ice there is now less water outside the cells. Water, in liquid form, tends to move from where there is more of it to where there is less of it. That's the process of osmosis and since there is suddenly less water outside the cells than there was, now the water moves out of the cells and dehydrates them, damaging them.

The second problem is caused when you freeze them quickly, like dunking them suddenly into a bath of liquid nitrogen. There is plenty of water inside the cells and it becomes ice crystals. Ice expands when it freezes (An oddity of water. Not all liquids are like that.) and the crystals cause severe damage to the cells.

So, if you want to freeze some cells you need a few things. You need to figure out the optimum rate of cooling and you probably need some mixture of solutes outside the cells that isn't toxic and can help keep the osmotic balance where you want it. These problems are solvable for thin layers of tissues where the cells are mostly similar or for individual cells of the same kind (like sperm) but large organs with lots of different kinds of tissues and cells in them pose greater problems that haven't yet been solved. You can't bathe all of the cells in the optimum solution (which might be different for different parts of the organ) and you can't freeze each of those tissues at the optimum rate.

True, we might solve the problem some day, but till then you might prefer to spend your money on things you can enjoy while you are alive, or you could donate it to you grandchildren's college fund. On the off chance that you don't have any grandchildren, I have paypal.

Links:

A simple and easy to understand description with diagrams.

The Society for Cryobiology

The abstract of a scientific paper about a method for figuring out if frozen bacteria are still viable.

Word (or phrase) of The Day

Osmotic Balance: This is defined differently for different situations but basically it always means that the water is staying where you (or the living system) want(s) it. In freshwater fish there is a higher water concentration outside the fish than in it. The fish has to keep too much water from invading its tissues and so pumps it out to maintain it's osmotic balance. In saltwater fish the situation might be the other way around. Remember, osmosis is all about water.