Freezing life

[curioucity]

Hello

I just had this question up in my head. Has anyone ever at the very least theorized/tested/proven that organic cells (and later, tissues, organs and, you guessed it, organism) can be reserved as long as it's kept in sheer cold (liquid gas temperature IIRC) ? Okay, I've read somewhere that scientists have succesfully reserved sperm for years, but have they done that to bigger form of life?

Come to think of it, I once saw on TV that a fly can lie dormant when frozen in dry ice temperature, but can suddenly 'live' again once it gets warmed enough. If the same is applied to bigger animals (say, reptiles, birds and so on), will we get the same result?

Thanks. I'll wait for an answer first before deciding whether to put a follow up question....

 

[Gondolin]

I had some dry ice a while back and put a frog on it. He seemed to have died but I took him off and heated him up and he proceeded to come back. So... yea.

 

[hypatia]

Sure. This is common in research labs. Worms (C. elegans) are easily frozen down and revived; flies (D. melanogaster) are a little more difficult, so people tend to keep their strains breeding.

For mammals, so far it hasn't been possible to freeze and revive an adult organism, but the technology to freeze fertilized embryos has been around for years, and it is now common to do this for both laboratory mice and people.

Some tiny little bugs like tardigrades don't even need to be frozen; they can just be dried out. They'll sporulate and stay that way for years, then revive with the addition of a little water.

 

[curioucity]

Hmmm....... so such researches (including your experiment, Gondo, thanks for sharing) have been conducted using small, non-hot blooded animals (in occasional different way, like that tardigrades case..). Okay, thanks for the info.
by the way, have those experiments been conducted on rather warmer temperature (like, slightly below water freezing point instead of super-cold ones)? If so, do those exps show considerably same results?

 

[Xerxes]

It depends...

Cells can be broken easily by the freezing process. If you kill too many, or if you kill the wrong ones, the body can't be revived (or it will die soon thereafter.) Mammals are incredibly complex, and our cells are fragile--explaining one reason why we're warm blooded. If we don't stay at a constant temperature, the cells can die.

Less complex organisms, esp bacteria can surive the freezing process.

Think of life as:
# of cells dying < # cells living.

If you can preserve the cells, you preserve life.

'Cryogenics' aims to fix the problem by replacing the blood with less harmful fluids..I won't even get into why its a stupid idea...

 

[patcho]

Eastern Wood frogs can survive freezing during winter by pumping glucose anti-freeze into their cells, their heart and brain activity stop. Then come alive after 2-3 months - I wonder if we could develop something like this...

 

[curioucity]

It depends...

Cells can be broken easily by the freezing process. If you kill too many, or if you kill the wrong ones, the body can't be revived (or it will die soon thereafter.) Mammals are incredibly complex, and our cells are fragile--explaining one reason why we're warm blooded. If we don't stay at a constant temperature, the cells can die.

Less complex organisms, esp bacteria can surive the freezing process.

Think of life as:
# of cells dying < # cells living.

If you can preserve the cells, you preserve life.

Hmmmm, when you mention it..... if I remember my Bio class back in High School correctly, some of human cells seem to have less organells compared to individual living cell, the erythrosyte(sp?) being such an example (missing a nucleus). Does this have to do with the cells you mention being fragile? But then again, are cold blooded animals' cells structure that different or something, even if the human cells' case is true?

Makes me wonder what actually happens to a cell when it's frozen. Obvious answer is that it will stop functioning, but in what way? I mean, how is the process that they stop functioning (like in, if they start storing anything, or stop an organel by an organell etc)?


Then, patcho, thanks for confirming that amphibians can survive cold (just like Gondo tested). Taking Xerxes' post into consideration as well, is it possible for reptiles to withstand cold? Birds should have problems just like mammals, being the other warm-blooded group...

 

[Nasor]

Eastern Wood frogs can survive freezing during winter by pumping glucose anti-freeze into their cells, their heart and brain activity stop. Then come alive after 2-3 months - I wonder if we could develop something like this...

I don’t think that these frogs actually freeze solid. They produce a natural antifreeze that allows them to hibernate in sub-zero temperatures without freezing.

 

[cardiovascular_tech]

you can deep freeze a cat and then warm him up back to life, the thing is the cat will live but be mentally retarded.

as far as humans go no its not possible at the moment but who knows what will come in the next 100 or so years, right now our organs have to be transplated pretty quick or the cells die an make the organ useless thats why you see people stuck on vents and such to maintain there organs til its time to transplate or at least harvest there organs.