Some time back there was a thread on obtaining DNA samples via normally shed particles in the air behind you. Found this: FEED: Theres been some talk of using the aura sniffer to do DNA analysis. GS: Yeah. But mitochondrial DNA -- not nuclear DNA. Were releasing skin all the time, so its not like being requested to give a DNA sample and having to give consent. You cant keep your skin from coming off. So it is possible to sample mitochondrial DNA from the airborne skin flakes. Of course, before this was ever done it would have to go through the same rigorous procedure and scrutiny by the ACLU and so forth that the other technology does. Im not advocating it. Im just saying that the possibility exists. The possibility also exists to sample a wide variety of medical conditions non-obtrusively. And I think that could end up being a valuable instrument for medical diagnosis. http://www.feedmag.com/re/re381.2.html