X-Message-Number: 17003 From: Date: Tue, 17 Jul 2001 02:35:46 EDT Subject: More fire fly results... Cryonet: Results from experiments outlined in my previous post on the fire fly experiments (post #16965; 7/12/2001) are as follows: * The fire fly frozen in a standard kitchen freezer with its ampoule full of water did not glow at all ever on retrieval, not even after the ice melted. I did not check to see if sectioning the abdomen would have worked. * The similarly prepared fire fly (with water) in liquid nitrogen did not glow either. * A fire fly who's lid (on the ampoule) was intentionally left loose such that LN2 might seep in to replace some air, did glow. It did not however seem to demonstrate the earlier described initial "black out" before its sustained glowing I was unable to determine how much LN2 replacement had occurred, while there certainly was some. I would categorize this test as "inconclusive" as there were too many variables including the likelihood of the fly being partially submerged in LN2 as well as a back and forth "washing" on removal creating greatly differing temperatures and uneven thawing. A better experiment will be to drill numerous tiny holes in such an ampoule with a fine drill bit (which will be very easy to do) or to use the sock method previously cited. * While fire flies frozen with water or submerged in LN2 with water never glowed at all on retrieval, I did find that the fly from the experiment described above continued to glow when submerged in water--until I got tired of watching it. I believe it would have done the entire 90 minutes. This tends to rule out the previously described potentiality of oxygen usage by passive diffusion from the flies abdomen area. I had planned to do a couple other experiments including placing a fly back in LN2 after it had been retrieved and was glowing to retrieve it again after a few minutes to see what effect there may have been. Would it have continued to glow or would the "double whammy" disable the reaction? I was also going to put such a glowing fly from the LN2 into the freezer in its open ampoule with the "outside temperature lead" of a standard indoor/outdoor thermometer inserted in with the fly to see when and how (i.e., what temperatures) and if the glowing ceased--and then remove it and see if it would resume. Early on the problem was that two ampouled flies came loose from their mountings and are now floating at the bottom of the dewar. Well, that fairly well guarantees that a couple of flies will get a several month long trial because I do not believe I am going to attempt to remove them for quite a while as I recently filled the tank to the top. In fact, it was the filling of the tank with LN2 that likely knocked the ampoules loose from their bindings on the string. I may do a few more with enough specimens for each experiment to get a decent level of confidence in the reliability of each experiment. We will see. Sorry. Kind of unfulfilling this time around. As some great early American writer one penned: "Such is the nature with the best laid plans of mice and flies" (or something kind of like that). Regards, David C. Johnson, Raleigh Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=17003