Cathal, Most of the research actually comes from disinterested research parties (search NCBI), not from paranoic state agencies. They are indeed safe, as long as one is not travelling inside a luggage bag. Regarding conflicts of interest, you will be aware that nearly all medications approved by FDA for human consumption, is based on clinical trials conducted by the companies that make them. That does not necessarily make the drugs bad. Jay
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Cathal Garvey Sent: Friday, September 21, 2012 10:22 AM To: [email protected] Subject: Re: RNA shipment A) They use backscatter for humans, regular transmissive X-rays for luggage. B) The figures for radiation exposure are extremely, perhaps deliberately, misleading. The degree of radiation is indeed lower, however the volume of tissue that absorbs that dose is far, far smaller than a regular X-ray, and the time taken to deliver the dose is far smaller than the usually-given comparisons to background radiation etc. The best analogy I have read on the matter is of a light bulb to a laser. A 100-watt lightbulb can be safely sat under for hours, but a 100-Watt laser will cut through you very quickly due to compression of dose area, a la skin vs. whole-body dosing in the case of backscatter scanners. I'd be less skeptical of their safety if most of the pro-safety arguments didn't come straight from the companies responsible for the machines, or paranoiac state agencies in the US. Also if routine reviews didn't keep discovering machines outputting orders of magnitude more radiation than intended. On 19/09/12 14:21, Jayakumar, R wrote: > The airport scanners are usually backscatter X-ray machines that have much > less ionizing radiation than the regular transmission ones used in hospitals. > Recent research into these airport scanners show that you have to be exposed > atleast 10 million times a year before you have a chance of getting one > cancer in your life time, and even that is questionable. Regarding RNA, > lyiphilising it should keep it pretty stable. Though X-ray induced damages > in RNA during transit, has not been well studied, it is possible it can cause > secondary structures or breakages in RNA. But remember that there are > millions of RNA molecules in that prep and it is unlikely that all the > molecules will break at the same point. We have shipped RNA and DNA samples > all across the world and never had any problems with its stability during > transit. > Jay > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Hiranya > Roychowdhury > Sent: Tuesday, September 18, 2012 4:29 PM > To: DK; [email protected] > Subject: RE: RNA shipment > > I had found one sure way to avoid degradation during shipment and/or storage > is to dissolve it in DMFA. It can subsequently be re-precipitated from it. > I agree with Dima that the radiation has to be rather high intensity to break > the RNA during routine X-ray (then again, I am not sure what the intensity > these days are. I opt out of the scanner at the airports). Thick lead > containers may be used to eliminate that possibility (secondary emissions > from thin lead foils may prove harmful too). > > > > Hiranya S. Roychowdhury, Ph.D. > Associate Professor > Health & Public Services > NMSU-Dona Ana Community College > 575 527 7725 (office) > > ________________________________________ > From: [email protected] > [[email protected]] on behalf of DK > [[email protected]] > Sent: Sunday, September 16, 2012 8:58 PM > To: [email protected] > Subject: Re: RNA shipment > > In article <[email protected]>, Peter > Ellis <[email protected]> wrote: >> Hiya, >> >> Has anyone had trouble sending or receiving RNA by air recently? We >> never used to have problems getting samples to or from collaborators: >> ship it on dry ice and as long as it stays frozen, it's fine. >> >> Recently we (and at least one other researcher in the Department) >> have been having problems with degradation en route. The samples are >> good condition when sent, stay frozen all the way, and yet are almost >> completely degraded on arrival. This has happened with flights to >> America and Japan. >> >> Have they introduced some new scanning of shipments (X-ray or >> similar?) that degrades RNA? > > That would be some really high intensity scan if it efficiently breaks RNA > when it is at -70C! That sort of power would be completely pointless, so I'd > discount this possibility. Sounds like human error somewhere: > The RNA is either degraded before shipment to begin with or whoever receives > it is not doing things right. > > - DK > _______________________________________________ > Methods mailing list > [email protected] > http://www.bio.net/biomail/listinfo/methods > > > > _______________________________________________ > Methods mailing list > [email protected] > http://www.bio.net/biomail/listinfo/methods > > > This email message may contain legally privileged and/or confidential > information. If you are not the intended recipient(s), or the employee or > agent responsible for the delivery of this message to the intended > recipient(s), you are hereby notified that any disclosure, copying, > distribution, or use of this email message is prohibited. If you have > received this message in error, please notify the sender immediately by > e-mail and delete this email message from your computer. Thank you. > > _______________________________________________ > Methods mailing list > [email protected] > http://www.bio.net/biomail/listinfo/methods > -- www.indiebiotech.com twitter.com/onetruecathal joindiaspora.com/u/cathalgarvey PGP Public Key: http://bit.ly/CathalGKey _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods This email message may contain legally privileged and/or confidential information. 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