Article

Chain and conformation stability of solid-state DNA: implications for room temperature storage.

Université de Bordeaux-plateforme Génomique Fonctionnelle, Institut Bergonié-INSERM U916 VINCO, Bordeaux, France.
Nucleic Acids Research (Impact Factor: 8.81). 12/2009; 38(5):1531-46. DOI: 10.1093/nar/gkp1060
Source: PubMed

ABSTRACT There is currently wide interest in room temperature storage of dehydrated DNA. However, there is insufficient knowledge about its chemical and structural stability. Here, we show that solid-state DNA degradation is greatly affected by atmospheric water and oxygen at room temperature. In these conditions DNA can even be lost by aggregation. These are major concerns since laboratory plastic ware is not airtight. Chain-breaking rates measured between 70 degrees C and 140 degrees C seemed to follow Arrhenius' law. Extrapolation to 25 degrees C gave a degradation rate of about 1-40 cuts/10(5) nucleotides/century. However, these figures are to be taken as very tentative since they depend on the validity of the extrapolation and the positive or negative effect of contaminants, buffers or additives. Regarding the secondary structure, denaturation experiments showed that DNA secondary structure could be preserved or fully restored upon rehydration, except possibly for small fragments. Indeed, below about 500 bp, DNA fragments underwent a very slow evolution (almost suppressed in the presence of trehalose) which could end in an irreversible denaturation. Thus, this work validates using room temperature for storage of DNA if completely protected from water and oxygen.

0 Bookmarks
 · 
174 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: A new procedure for room-temperature storage of DNA was evaluated whereby DNA samples from human tissue, bacteria, and plants were stored under an anoxic and anhydrous atmosphere in small glass vials fitted in stainless-steel, laser-sealed capsules (DNAshells(®)). Samples were stored in DNAshells(®) at room temperature for various periods of time to assess any degradation and compare it to frozen control samples and those stored in GenTegra™ tubes. The study included analysis of the effect of accelerated aging by using a high temperature (76°C) at 50% relative humidity. No detectable DNA degradation was seen in samples stored in DNAshells(®) at room temperature for 18 months. Polymerase chain reaction experiments, pulsed field gel electrophoresis, and amplified fragment length polymorphism analyses also demonstrated that the protective properties of DNAshells(®) are not affected by storage under extreme conditions (76°C, 50% humidity) for 30 hours, guaranteeing 100 years without DNA sample degradation. However, after 30 hours of storage at 76°C, it was necessary to include adjustments to the process in order to avoid DNA loss. Successful protection of DNA was obtained for 1 week and even 1 month of storage at high temperature by adding trehalose, which provides a protective matrix. This study demonstrates the many advantages of using DNAshells(®) for room-temperature storage, particularly in terms of long-term stability, safety, transport, and applications for molecular biology research.
    Biopreservation and Biobanking 06/2014; 12(3):176-183. · 1.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Verticillium wilts are important vascular wilt diseases that affect many crops and ornamentals in different regions of the world. Verticillium wilts are caused by members of the ascomycete genus Verticillium, a small group of ten species that are related to the agents of anthracnose caused by Colletotrichum species. Verticillium has a long and complicated taxonomic history with controversies about species boundaries and long overlooked cryptic species, which confused and limited our knowledge of the biology of individual species. We first review the taxonomic history of Verticillium, provide an update and explanation of the current system of classification and compile host range and geographic distribution data for individual species from ITS GenBank records. Using Verticillium as an example, we show that species names are a poor vehicle for archiving and retrieving information, and that species identifications should always be backed up by DNA sequence data and DNA extracts that are made publicly available. If such a system were made a prerequisite for publication, all species identifications could be evaluated retroactively, and our knowledge of the biology of individual species would be immune from taxonomic changes, controversy and misidentification. Adoption of this system would improve quarantine practices and the management of diseases caused by various plant pathogens.
    Phytopathology 02/2014; · 2.97 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Molecular dynamics simulation and biophysical analysis were employed to reveal the characteristics and the influence of ionic liquids (ILs) on the structural properties of DNA. Both computational and experimental evidence indicate that DNA retains its native B-conformation in ILs. Simulation data show that the hydration shells around the DNA phosphate group were the main criteria for DNA stabilization in this ionic media. Stronger hydration shells reduce the binding ability of ILs' cations to the DNA phosphate group, thus destabilizing the DNA. The simulation results also indicated that the DNA structure maintains its duplex conformation when solvated by ILs at different temperatures up to 373.15 K. The result further suggests that the thermal stability of DNA at high temperatures is related to the solvent thermodynamics, especially entropy and enthalpy of water. All the molecular simulation results were consistent with the experimental findings. The understanding of the properties of IL-DNA could be used as a basis for future development of specific ILs for nucleic acid technology.
    Physical Chemistry Chemical Physics 06/2014; · 4.20 Impact Factor

Full-text (2 Sources)

Download
46 Downloads
Available from
May 22, 2014