Urgent:Radiation and mutation..

Wolf Wolf at your.mom.com
Sun Oct 24 11:49:43 EST 1999


Correction...

Radiation level is 1-2 MR/HR.

On Sun, 24 Oct 1999 07:02:11 GMT, "Wolf" <pianoman at mindless.com>
wrote:

>Thanks for the info....
>
>well, I knew a couple of guys in the lab injected 59Fe into mice and
>isolated the organs.
>These organs have been stored in -80 freezer and they keep adding new
>organs.
>The way I found out about this was a few days ago I exposed my gel to the
>film which was stored for 1 days on the top of this organs by accident.  The
>film came out mostly dark.  First, I though some jerk exposed the film to
>the light.
>Today, I got my glycerol stocks from the freezer and isolated the plasmids.
>Strangely, I could not digest DNA pieces with the enzymes which used to work
>fine.
>The strangth of Geiger reading is about 1-2 BMP.
>
>But, I don't understand how DNA or molecules could be damaged by radiation
>at -80 degree.
>
>If this is the case, I have to throw out my whole glycerol stocks.
>
>Thank you very much.
>redflag wrote in message <381285A0.8A8AAC64 at videotron.ca>...
>>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
>>measurement.
>>You can get info about this assay at
>>http://www-hotel.uu.se/occmed/forskning/scg/scg.html
>>
>>Hope this helps,
>>
>>Seb.
>>
>>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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