RNA shipment

Cathal Garvey via methods%40net.bio.net (by cathalgarvey from gmail.com)
Fri Sep 21 09:22:03 EST 2012


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: methods-bounces from oat.bio.indiana.edu [mailto:methods-bounces from oat.bio.indiana.edu] On Behalf Of Hiranya Roychowdhury
> Sent: Tuesday, September 18, 2012 4:29 PM
> To: DK; methods from magpie.bio.indiana.edu
> 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: methods-bounces from oat.bio.indiana.edu [methods-bounces from oat.bio.indiana.edu] on behalf of DK [dk from no.email.thankstospam.net]
> Sent: Sunday, September 16, 2012 8:58 PM
> To: methods from magpie.bio.indiana.edu
> Subject: Re: RNA shipment
> 
> In article <Pine.LNX.4.64.1209141041280.23885 from hermes-1.csi.cam.ac.uk>, Peter Ellis <pjie2 from cam.ac.uk> 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
> Methods from net.bio.net
> http://www.bio.net/biomail/listinfo/methods
> 
> 
> 
> _______________________________________________
> Methods mailing list
> Methods from net.bio.net
> 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
> Methods from net.bio.net
> http://www.bio.net/biomail/listinfo/methods
> 

-- 
www.indiebiotech.com
twitter.com/onetruecathal
joindiaspora.com/u/cathalgarvey
PGP Public Key: http://bit.ly/CathalGKey



More information about the Methods mailing list