Rapid and zero-cost DNA extraction from soft-bodied insects for routine PCR-based applications

Nucleic acid extraction is the first and foremost step in molecular biology studies. Extraction of DNA from small, soft-bodied insects is often time-consuming and costly. A fast, easy, and cost-effective DNA extraction method with greater yield and purity of DNA would aid in the rapid diagnostics, screening of large populations, and other routine PCR-based applications. The present study evaluated and standardized a rapid and zero-cost DNA extraction from soft-bodied small insects for routine molecular studies. Five rapid DNA extraction methods viz. extraction in sterile distilled water (SDW), 1X phosphate-buffered saline (PBS, pH 7.4), 1.4 M sodium chloride (NaCl), 20 mM ethylenediaminetetraacetic acid (EDTA, pH 8.0), and elution from blotted nitrocellulose membrane (NCM) were compared with standard CTAB extraction buffer and DNeasy(®) Blood and Tissue Kit methods. The average yield, purity, storage stability, time, and cost of extraction were assessed for all the methods and compared. A method of DNA extraction by simply crushing the soft-bodied insects in SDW was ideal in terms of yield, purity, storability, and performing routine PCR-based applications including detection of pathogens from vector species. The extraction could be accomplished in 2.5 min only with zero-reagent cost. The method would be useful in rapid molecular diagnostics and screening large populations of soft-bodied insects.