Biodiversity Institute of Ontario, Department of Integrative Biology, University of Guelph, Ontario, Canada.
Biotechniques. 2010 Mar;48(3):233-4. doi: 10.2144/000113362.
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.
DNA 提取是许多分子生物学方案的第一步。然而，我们假设保存样本中的 DNA 可能会渗漏到其保存介质中，从而使介质本身能够直接进行 PCR 扩增。我们在龙舌兰酒上成功地验证了这一想法，龙舌兰酒是一种以装在许多品牌酒瓶中的“虫子”（毛毛虫）而闻名的酒精饮料，并且确实获得了可扩增的毛毛虫 DNA 量。然后，我们成功地扩增和测序了 70 个新鲜采集的标本和 7 个保存了 7-10 年的存档标本的 95%乙醇保存液中的 DNA。这些结果表明，在许多方案中，DNA 提取是多余的步骤，保存用的乙醇可以作为遗传物质的来源，用于非侵入性采样，或者当没有组织标本留作进一步的 DNA 分析时使用。
