Urgent:Radiation and mutation..

redflag scharpen at videotron.ca
Sat Oct 23 23:05:52 EST 1999

Hi Wolf,

59Fe is a beta(-) emitter with a period of 44.6 days. I have no
information about its energy, but as the period is relatively short, this
radionuclide probably has a strong activity.

You says that radioactivity is sill very high. Have you got an idea of the
level ? Did you get the radioactivity level with a Geiger-Muller meter ?
Was the radioactive source inside the -80°C freezer ? Do you know its
nature ? Is the source old or not ?

Even without this information, I am pessimistic. If your stocks really
have been exposed for more than 2 months, the DNA and others molecules has
undoubtedly been damaged.
Depending on the dose they received, cells might grow or not grow when put
in culture. Double stranded  breaks (dsb) are lethal, when single strand
breaks (ssb) can be repaired. Point mutations are mainly non-lethal.

What you can do is extract a sample DNA from your irradiated stock and
deposit it on gel for migration. PFGE would be better to see if the DNA is
degradated. Many strips on your gel would mean that the DNA is fragmented,
and thus there's nothing to do with, unless you want to study "hot points"
of  induced mutations...

You can also do a comet assay, which is a specific-damaged DNA
You can get info about this assay at

Hope this helps,


Sébastien Charpentier, MSc, Radiation Biology.
scharpen at videotron.ca

Wolf a écrit :

> Hello People...
> I don't think this is the proper site for posting but I think I might
> get some answers for my question.
> I just find out that my E.Coli and yeast glycerol stocks have been
> exposed to high radiation by 59Fe for more than  2 months.  The
> radioactivity is still very very high.
> Is it possible to have any effects on my glycerol stock from radiation
> such as mutation or whatever possible damage?
> Thank you very much for any comments.

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