killing and preserving
Doug Yanega
dyanega at pop.ucr.edu
Mon Jul 21 15:51:19 EDT 2003
>What are ways to kill and preserve insects (espescially moths) so that they
>can be used in the future for DNA examinations? What are the poisons and
>preservatives to be avoided? Thanks for any help.
Avoid *prolonged* exposure to ethyl acetate, and high temperatures.
Other than that, most conventional killing methods don't harm the
DNA. The key factor in DNA preservation is what happens once the
insect is dead. When we need to sequence leps, we simply remove a
middle leg immediately and stick it in 95% ethanol in a freezer with
a cross-referenced label to keep it associated with the voucher
specimen. 95% isopropyl is almost as good - it's not so much the kind
of alcohol, as the concentration, that helps DNA preservation
(evidently based on the speed with which water is eliminated from the
tissue). Even dry specimens can give good DNA results *IF* they dry
out completely and *quickly* (if the tissue doesn't dry fast enough,
it rots, and becomes useless for sequencing). Low temperatures also
reduce DNA breakdown, while high temperatures greatly accelerate it.
Hope this helps,
--
Doug Yanega Dept. of Entomology Entomology Research Museum
Univ. of California - Riverside, Riverside, CA 92521
phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
http://cache.ucr.edu/~heraty/yanega.html
"There are some enterprises in which a careful disorderliness
is the true method" - Herman Melville, Moby Dick, Chap. 82
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