[NHCOLL-L:2852] Preserving specimens for DNA extraction

[Brad Hubley]

Apologies to cross-posting to both lists, but I need all the help I can
get as I am not familiar with molecular techniques.
 
One of our staff recently brought back from the Northwest Territories,
a couple dozen Malaise trap samples containing thousands of small,
flying insects that were preserved in 95% ethanol (he wants to extract
DNA from his specific group of insects within these samples).  Typically
we store such collections in 80%; in 95% the specimens are much more
brittle and difficult to handle without breaking off setae, etc.
 
Given that we may want to extract DNA from other taxa within these
collections at some future date, what is the best way to preserve these
samples over the long-term?  Should they remain in 95% or can they be
moved into 80%?  Our DNA lab techs say we should continue to preserve in
95% and place the specimens into an ultra-cold freezer -- but then we
run the risk of damage to the actual specimens.
 
So we feel we are faced with a dilemma, preserve for DNA extraction,
preserve for morphology, or can we preserve for both?  
 
Thanks in advance to all who reply and if anyone needs further
information from me, please give me a shout.
 
Brad
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
  Brad Hubley
  Entomology Collection Manager
  Department of Natural History
  Royal Ontario Museum
  100 Queen's Park, Toronto, Ontario           
  Canada    M5S 2C6
 
  Phone:  1-416-586-5764 
  FAX:      1-416-586-5553 
  email:  bradh at rom.on.ca 
  Visit our website at: http://www.rom.on.ca/ontario/ 
 
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