The role of naturally occurring D in living organisms has been examined by using deuterium-depleted water (30-40 ppm D) instead of water containing the natural abundance of D (150 ppm). The deuterium-depleted water significantly decreased the growth rate of the L929 fibroblast cell line, and also inhibited the tumor growth in xenotransplanted mice. Eighty days after transplantation in 10 (59%) out of 17 tumorous mice the tumor, after having grown, regressed and then disappeared. We suggest that the naturally occurring D has a central role in signal transduction involved in cell cycle regulation. - Steve Koch

This is one of those papers you have to read (and while you're reading it, I'm patenting my deuterium-depletion filter for home use and sending the press release to the daily mail, national enquirer, and Oprah). - Mr. Gunn

I haven't read it yet. Are you hinting that it's good or bad? - Steve Koch

Haven't read it yet either - Mr. Gunn

Not having read it, it could be that whatever they're doing to deplete the deuterium is leaving some harmful stuff in the water, and that certainly sounds more likely, but one would think the editorial process would weed out such obvious mistakes, but mistakes do happen and I've seen some crazy stuff come out of eastern european labs and the related articles are also all kinda obscure, but prions and transposons were once thought to be crazy fringe ideas too... - Mr. Gunn

Well, you may be onto something. In methods, they say, "Deuterium-depleted water (30-40 ppm D) was obtained from tap water (150 ppm) by electrolysis," ... Seems a bit sketchy to use tap water, even in 1993. ... All that aside, I've been a quite surprised this weekend at how drastically D versus H can change the chemistry of things. I'd been inappropriately biased towards thinking the main effect of heavy water would be in physical kinds of things (like diffusion, viscosity, fugacity, vapor pressure) or nuclear things (like slowing down neutrons). Now, I know that D versus H can affect chemistry too and strongly. So, it doesn't seem too crazy to me that depletion of D would affect cell processes. Apparently, the natural concentration of D in water is 8 mM, which is pretty high when thinking of chemical effects. - Steve Koch

Steve, could you give an example of a case where D versus H is known to change the chemistry? I, too, had (have) the bias you mention. - mkz

@mkz, there're some general examples at wikipedia "kinetic isotope effect" http://en.wikipedia.org/wiki... ... There are also reports that heavy water tastes differently than H2O (can't find link now), which would most likely be chemistry (right?). The strong toxicity of heavy water to eukaryotic cells also argues for chemical effects. I guess I don't know the best example. - Steve Koch

A grad student in our lab, Andy Maloney, did a kinesin motility assay in heavy water on Friday and saw an amazing array of cool effects (http://openwetware.org/wiki...) ... At this point, is tough to figure out the science, but it's nevertheless very exciting. One thing we want to try is to compare D2O to water with 18-Oxygen isotope. This could be one way of separating deuterium/protium chemistry from the simple mass differences of the solvent. Sort of expensive (18-O water is like $200 / gram), but definitely worth it for the science! - Steve Koch

Wow, I didn't know heavy water was toxic. I figured the vibrational spectra would change when you change the isotope, and guessed minor changes in molecular structure could similarly occur, but it seems the effects are much more pronounced than that. - mkz

Those experiments look interesting! (Not that I know much about the field.) D2O versus H2(O18) sounds like an interesting experiment, too, hopefully we'll be able to follow the results here. - mkz

I know, amazing, huh? (heavy water toxicity) The funny thing is I was thinking D2O would be a simpler way of probing water activity, compared with osmotic stress. Ha! - Steve Koch

As for the experiments, Andy is an Open Notebook Science (ONS) practitioner, so all his results (as of now) will be available. It's actually been a conundrum for me this weekend as to whether or not to advertise his results. A good case study in ONS--on the one hand, I'm super-excited. On the other hand, we don't know what's going on, and I feel like he may prefer some time to figure some things out. Who knows? Glad you liked his experiments! - Steve Koch

@mkz, I put some thoughts on Andy's notebook's "talk" page here: http://openwetware.org/wiki... I was amazed to find out they actually use D2O to stabilize proteins in vaccines. - Steve Koch

It is indeed a good case study in ONS, I'm happy to hear the results will be available, but I'd understand if you guys changed your minds. I'm not sure how open I could bring myself to be when I make a discovery, waiting to be explained/utilized. Good luck with the project. - mkz

Just looked at your comments, reading that page was fun (and heavy water ice sinks in water?--nice). - mkz

Going to bed now, thanks for your comments. - mkz

Good night, and thanks for your thoughts! - Steve Koch

Steve the videos on Andy's page you link to look awesome but I'm not sure I understand exactly what was done - is there a section with the experimental details or is that what you guys are debating whether or not to release? - Jean-Claude Bradley

@Jean-Claude: What specifics would you like to know? I'm still in the process of making my experimental procedure available on OWW of which I will link to in my notebook. So, I apologize if things are still in disarray when it comes to the specifics of how I do things. - Andy Maloney

There's no debate on releasing anything--all info is desired to be public. In fact, there's no debate at all except in my own mind--as to whether to specifically invite people to look at the results (which I did above) via a blog post or other. @Andy, I think what Jean-Claude is saying is that it's very much not evident what your experimental methods are, mostly because of the challenges of the OWW notebook. When I look at your page, it's not obvious that "Heavy PEM-kappaC" has a specific recipe page. And you don't say, "following protocol [[link]] with no changes" etc. - Steve Koch

Andy - I was looking for which materials and in what amounts were added at what times to understand the videos and the effect of the deuterium. I'm intrigued by the effect of isotopes in chemical processes and I think your experiments could yield valuable insight. We've also very briefly looked at the effect of deuteration on smell http://usefulchem.wikispaces.com/Exp218 because of the putative detection of molecular vibration in receptors - Jean-Claude Bradley

It's worth noting that most commercial D2O is pretty filthy from a colloid chemistry perspective. Strictly speaking ultrafiltration or reverse osmosis is required to get to the kind of water quality one routinely expects these days for the normal stuff. But it's way too expensive to blow 10 L of D2O on getting a water purifier fully exchanged... - Cameron Neylon

Jean-Claude: Yep, this is going to take a while to clean up and do what you ask. I'm really motivated right now to start an experiment so, I will have to come back to this later tonight. I'll let you know when I have a draft for a materials and procedure page. - Andy Maloney

from a completely different perspective, then it wouldn't be a good idea to use a D20 moisture mist? The latest thing in cosmetics: http://snipurl.com/t0vih - Mickey Schafer

@Jean-Claude, cool smell experiment! (Is row 2A mislabeled, or am I misreading?) I've been wanting to try some kind of isotopic smell thing ever since reading the Turin book. - Steve Koch

@Cameron thanks for that tip. We're keeping it in mind now that the results could be attributable to contaminants. Question: It's definitely too expensive for us to think of doing that. But wouldn't Sigma be able to afford doing so? - Steve Koch

@Mickey: good find! - Steve Koch

Steve - thanks yest that was a mislabeling and it is fixed now - although note that (as indicated in the conclusion) the results in the table are not meaningful. Designing a statistically valid test like this is harder than it might seem and would require many more samples. The best I would hope from this experiment is to motivate a few more researchers to take a few minutes and sniff - do they find the same: Acetone and methanol had strong differences from their deuterated versions while benzene and chloroform did not. - Jean-Claude Bradley

Thanks Andy - I'm not asking to write a full report. It is probably enough to just post the experimental notes. In our lab that would correspond to the "log" section, whereas the full well formatted report is the "procedure" section to be written later. (e.g. http://onschallenge.wikispaces.com/Exp130 ). If that isn't how you keep track of experiments could you let me know what constitutes a typical workflow? I know that different fields can record experiments very differently - for example speaking with Heather Etchevers it was interesting to learn that because molecular biology experiments are so fixed (and don't require observations so much) that there is no need to keep a log - her students just follow a pre-determined procedure. - Jean-Claude Bradley

Hey Jean-Claude, Interesting smell reference in a review I'm reading: "2.5.1. Olfaction in fish. Hara [40] investigated the ability of the whitefish, Coregonus clupeaformis, to distinguish between the odor of glycine (Gly) and fully deuterated glycine (Gly-ds). Over the concentration range of 10^-8 to 10^-4 M, these fish avoided solutions of Gly-ds and preferred solutions of Gly." From: http://www.ncbi.nlm.nih.gov/pubmed... Also some interesting insect olfaction stuff: "Wang [42] showed that perdeuteration of acetaldehyde (-do vs. -d4) and acetone (-do vs. -d6), and partial deuteration of methanol (-do vs. -dl ) and 2-butanone (-do vs. -ds), eliminated the aggregation and oviposition responses of red flour beetles to all of these compounds, except methanol-dl ." - Steve Koch

Interesting thoughts from Lewis in his 1934 Science paper on biological effects of heavy water (relevant to the FEBS paper originally linked in this thread): "It is not inconceivable that heavy hydrogen, which exists in small amounts in all natural water, may actually be essential to some plants or animals. A supply of water almost completely freed from the heavy isotope is now being prepared for the purpose of conducting such studies." - Steve Koch