title: Direct PCR amplification and sequencing of specimens' DNA from preservative ethanol.
abstract: DNA extraction is the first step in many molecular biology protocols. However, we hypothesized that DNA from a preserved specimen can leak into its preservative medium, allowing the medium itself to be directly PCR-amplified. We successfully tested this idea on mescal-the alcoholic beverage famous for the "worm" (a caterpillar) that is placed in the bottle of many brands-and indeed obtained amplifiable quantities of caterpillar DNA. We then successfully amplified and sequenced DNA from the 95% ethanol preservative of 70 freshly collected specimens and 7 archival specimens 7-10 years old. These results suggest that DNA extraction is a superfluous step in many protocols and that preservative ethanol can be used as a source of genetic material for non-invasive sampling or when no tissue specimen is left for further DNA analyses.
authors.affiliation: Biodiversity Institute of Ontario, Department of Integrative Biology, University of Guelph, Ontario, Canada.
authors.forename: Shadi
authors.initials: S
authors.lastname: Shokralla
authors.forename: Gregory A C
authors.initials: GA
authors.lastname: Singer
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hajibabaei
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis; D000818:Animals; D002080:Butterflies / Q000235:genetics; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D000431:Ethanol / Q000737:chemistry*; D018514:Plant Structures / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D017422:Sequence Analysis, DNA / Q000379:methods*; D013048:Specimen Handling / Q000379:methods*
chemical_list: D000431:Ethanol; D004247:DNA