DNA extraction from varnished insect bodies - (Jul/20/2012 )
Do you guys have any experience with DNA extractions from insects to which a large amounts of varnish is applied before for preservation purposes? I will have to proceed PCR and sequencing later, so the method i m going to get rid of the varnish should not be inferfered with those. Dipping in alcohol.! will it be alright??
Methanol and ethanol and isopropanol will all be fine, they preserve DNA intact and are commonly used in DNA extractions. I don't know about things like butanol or any of the higher chain alcohols. Xylene will probably be fine too, as people quite often extract DNA from paraffin fixed, wax embedded samples.
I guess it also depends on the type of varnish...some are only soluble in stuff like turpentine and other organic solvents (acetone, mineral spirits). Or you continue with extraction without removing varnish by opening body parts mechanically (e.g. grinding,..).
And was the insect in ethanol or dried before varnishing? If not, you might have the problem that the insect's water could not evaporate (sufficiently) and then decay could take place resulting in degradation of DNA...