dna preservation

[Chris J. Durden]

Thanks. This is just the kind of information we collectors and curators need.
    I have started labelling specimens I have caught as "killed by pinching 
and air-dried" as a notice for future researchers that they were not 
subjected to cyanide, carbon tetrachloride, chloroform, ether etc. I would 
advise other collectors to do the same.
    How about past use of fumigants in the collection? How does exposure to 
fumes of carbon disulphide, naphthalene flakes, paradichlorobenzene, 
dichlorvos. pyrethrum powder, oil of cedarwood etc. affect the stability of 
DNA in dried specimens. This is really important for conservation of 
samples of extinct populations like the Xerces Blue.
    If you are working with lepidopteran DNA, please let us collectors and 
curators know how to handle the specimens for maximum benefit.
.............Chris Durden


At 03:34 PM 7/20/2001 +1000, you wrote:
>I've never heard that DNA is damaged by water.  It would be hard to imagine
>how it could survive in the cell if it was.  I routinely dissolve
>precipitated, purified  DNA in water and freeze it as a means of storage.
>However, as far as storing animal body parts goes to optimize DNA yield the
>best way is freezing preferably at approx.-70 degrees C, but -20 degrees C
>seems to work fine for the moths I'm working with.  If this is too
>difficult storing in absolute ethanol, preferably keeping them cold as
>well, seems to work almost as well for some organisms.  I've also
>successfully extracted DNA from pinned, dried specimens up to 10 yrs old.
>Other people I know have done the same from 80 yr old specimens.
>   I guess DNA is a remarkably stable molecule.  It needs to be otherwise
>things can go terribly wrong in organism development.   I've also just
>heard that chloroform killed specimens are almost impossible to extract
>from.



 
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