The appropriate preservation of the DNA of a certain organism is important for successful application of molecular techniques like RAPD-PCR. This study was designed to compare simple methods of preservation of specimens of Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae) with respect to quantity and quality of DNA for use in RAPD-PCR, after different storage periods. Eight methods were tested: freezing (-20ºC); ethyl alcohol 70% (-20ºC and room temperature); absolute ethyl alcohol (-20ºC and room temperature); air-dry; and preservation in extraction buffer (whole and homogenized insect). At intervals of 10 to 30 days, insect DNA was extracted, quantified and amplified through RAPD-PCR using primer OPA-04. The quality of extracted DNA was observed on 0.8% agarose gel. After 210 days of preservation, freezing (-20ºC) showed to be the best method. Satisfactory quantities of DNA were also obtained from insects conserved in absolute ethyl alcohol (-20ºC), ethyl alcohol 70% (-20ºC) and extraction buffer (whole and homogenized insect). Insects conserved in absolute ethyl alcohol (room temperature), ethyl alcohol 70% (room temperature) and air-dry conditions were inappropriate for RAPD-PCR studies after 120, 60 and 10 days of storage, respectively.
Insecta; corn leafhopper; molecular marker; DNA conservation; storage technique
