Adults of each insect species were individually
ground in 400 μl of cold extraction buffer (10 mM Tris, pH 8.0, 0.1 M
EDTA, 20 μg/ml RNase and 0.5% SDS)
The ground sample was
incubated at 50 °C for 10 min with 5 μl of proteinase K (20 mg/ml).
To remove macromolecules other than nucleic acids, a mixture of
phenol (pH 8.0) and chloroform (1:1, v/v) was added in a volume
equal to the bground?N sample.The mixture was then centrifuged at
14,000 rpm for 2 min. The upper layer was removed and mixed with
an equal volume of a mixture of chloroform and isopropyl alcohol
(24:1, v/v). Genomic DNA was then isolated by ethanol precipitation
and resuspended in sterilized deionized water