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Abstract Detail



Botanical DNA Banking and the Systematics Community: Working Together to Meet Future Research Challenges

Neubig , Kurt Maximillian [1], Whitten, W. Mark [2], Abbott, J. Richard [3], Elliott, Savannah [4], Soltis, Douglas E. [5], SOLTIS, PAMELA S. [2].

Variables affecting DNA preservation in archival plant specimens.

Although the use of plant DNA in scientific research is now decades old now, we still know very little about the best methods of DNA preservation. Few studies have focused on aspects of DNA quality and preservation, and as a consequence, a broad sense of the quality of DNA in herbarium specimens and tissues specifically preserved for DNA usage is still lacking. To address lingering questions about the nature of DNA quality in archival plant specimens, we evaluated ~2000 samples from herbarium specimens, as well as silica-dried and frozen tissues specifically preserved for DNA usage. For herbarium specimens, we used materials with alternative curation histories, and sampling spanning much of angiosperm phylogenetic diversity to ascertain general trends of DNA degradation over time and to assess whether different clades had different rates of “expiration.” Our results indicate different rates of DNA degradation, and that specimen curation history has a strong influence on DNA quality. For frozen tissues, virtually all samples had excellent quality, whether storage was at -20° or -80°C and whether tissue was pulverized or intact. For silica-dried tissues, the results were much more heterogeneous; samples stored in vessels with poor seals yielded lower-quality DNA. To address the long-term viability of frozen DNA extracts, we compared a set of 7–12-year-old DNA extracts with new extracts of the same original silica-dried tissues and with fresh, greenhouse-collected tissues of the same original material; these comparisons indicated less degradation in the extracts than in the silica-preserved samples, although the differences were subtle. We also found that 15-year-old photo-bleached, silica-dried samples still had small amounts of high-molecular-weight DNA. The long-term preservation of DNA in archival samples remains problematic, but we can best preserve DNA by limiting the factors that degrade it. Although the botanical community has been preserving tissues and DNA extracts for a limited timespan, we can infer some basic conclusions from this and other studies. Recommended best practices are to freeze tissues and extracts at as low a temperature as possible (e.g., -80°C), but if that is not possible or practical, room temperature storage of tissues with silica in tightly sealed containers is a viable alternative, at least for the short term.


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1 - University Of Florida, 4007 SW 20th Ln, Gainesville, FL, 32607, USA
2 - University Of Florida, Florida Museum Of Natural History, PO BOX 117800, Gainesville, FL, 32611-7800, USA, 352/273-1964
3 - Missouri Botanical Garden, P O Box 299, St Louis, MO, 63166-0299, USA
4 - University of Florida, Biology, Gainesville, FL, 32611
5 - University of Florida, Florida Museum of Natural History, Gainesville, FL, 32611

Keywords:
DNA
preservation.

Presentation Type: Symposium or Colloquium Presentation
Session: SY07
Location: Whitewater/Grove
Date: Tuesday, July 29th, 2014
Time: 2:30 PM
Number: SY07003
Abstract ID:83
Candidate for Awards:None


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