mail irradiation & biological macromolecules... what now?

Duncan Clark junk at
Tue Feb 26 07:28:28 EST 2002

Historians believe that in newspost <3c74bd49$1 at> on Thu, 
21 Feb 2002, Roland Hübner <roland.hubner at> penned the following 
literary masterpiece:
>>Such treatment most likely would damage DNA samples being sent through
>>the post for research purposes, including extacted DNA or dried samples
>>in blood, etc. Does anyone have experience in recent weeks in shipping
>>DNA samples? Will researchers be required in the future to use the
>>private services, such as Federal Express in the US?
> Linked or dried DNA is usually better off than nucleic acids in solution
>when UV irradiation, but here the aim is to break down also such
> This is a more targeted question about the general theme of which
>reagents we use in our bench work might be wrecked by this technology...
>(e.g., can this affect autoradiographic films, (charged) membranes, etc.)
> Anybody heard/learned anything specific about this aspect?

We recently ran a test on having microtubes gamma irradiated to save us 
autoclaving them by the thousands. The irradiation was done at Isotron, 
UK at various dose levels up to medical sterilization does levels. The 
polypropylene ages and turns pale yellow with increasing dose and we are 
talking about several hours of irradiation.

So what happened.

We spiked some tubes with 1ug of lambda (48.5kb) DNA (dried down), 
irradaited the tubes and then ran a quantitative PCR assay one all dose 
levels amplifying a 100bp target using a Taqman probe, running from 10E7 
copies down.

At no dose level did we detect any loss of DNA, even though the plastic 
was effected!

There may well be breaks in the DNA but they had no effect in our assay.

It may stop an organism being viable but you will pick up the DNA fine.

The problem with being on the cutting edge is that you occasionally get
sliced from time to time....

Duncan Clark
GeneSys Ltd.

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