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 >********************* > > > Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=9191