Non-destructive DNA extraction from specimens and environmental samples using DESS preservation solution for DNA barcoding

DESS is a widely used storage solution for the preservation of DNA from biological tissue samples. DESS comprises 20% dimethyl sulfoxide, 250 mM ethylenediaminetetraacetic acid, and saturated sodium chloride, and its efficacy has been confirmed in various taxa and tissues. DESS enables the stable, long-term preservation of both sample morphology and DNA. However, to access the DNA, excising a portion of the sample was necessary. Although DNA is a valuable source of information for species identification, DNA extraction can result in the loss of an entire sample or segment, especially in small-sized organisms, thereby compromising specimen value. Therefore, establishing non-destructive DNA extraction techniques is imperative. Thus, this paper presents a protocol for conducting non-destructive DNA extraction and DNA barcoding using a portion of the DESS supernatant obtained from a nematode specimen. This method was successfully employed for DNA barcoding of nematodes that were stored in DESS at room temperature (-10~35˚C) for ten years. Moreover, the method can be potentially applied in the preservation and non-destructive extraction of DNA from specimens of various species. Following sample collection, a bulk environmental sample from sediment and seagrass is immediately immersed in DESS in the field. Subsequently, DNA is extracted from the supernatant solution, allowing non-destructive DNA barcoding. Overall, this paper presents comprehensive protocols for DNA extraction from DESS supernatants and demonstrates their practical application using meiofauna (small animals) and diatoms as examples.