X-Message-Number: 9191
From: Olaf Henny <>
Subject: Re: Doug Skrecky Cryonet #9190
Date: Mon, 23 Feb 1998 07:24:31 -0800

I laughed so hard, that I spilled my morning coffee all over 
my pants.  Now I have to go and change. :)
>
> Goal: Test the effect of various cryoprotectants on the freeze/thaw
> survival of drosophilia melanogaster flies.
>
> Procedure: Add cryoprotectant to commercial 4-24 fly food. Feed this to
> flies for several days. Then freeze the flies overnight in
> refrigerators's freezer. Thaw the next day and look for survivors.
>
> Note: With glycerol half the water added to the fly food was replaced by
> this liquid. With the other cryoprotectants, which are solid at room
> temperature, equal volumes of cryoprotectant and 4-24 fly food were mixed
> together, prior to addition of water.
>
> Results:
>    Toxicity of cryoprotectant was roughly judged based on mortality prior
> to freezing. Based on this the substances used can be ranked in order of
> decreasing toxicity as follows: alanine, glycine > glycerol, proline >
> glucose, glutamine.
>    Percentage survival after freezing/thawing is as follows:
>
>    alanine: 0%
>    glucose: 0
>  glutamine: 0
>   glycerol: 0
>    glycine: 0
>    proline: 0
>
> Conclusions:
>
>    Drosophilia melanogaster is not an appropriate experimental model for
> testing cryoprotectants. Possibly a more freeze resistant insect might be
> useful for ranking the effectiveness of various cryoprotectants.
>
>----------------------------------------------------------------------
>
>End of CryoNet Digest
>*********************
>
>
>

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