May 11-14, 2010
IMAGENE présente le 13 mai durant ce grand rendez-vous annuel sur les biobanques, une communication « New Technology for Room Temperature Storage of DNA ».
BACKGROUND: One of the challenges regarding DNA repositories is the exponentially increasing number of samples to be preserved making classical freezer storage unreliable and prohibitively costly. An appealing solution is room temperature storage of dehydrated DNA but we recently showed that storage in air is inadequate for optimal DNA conservation at room temperature. Indeed, we showed that solid-state DNA degradation is greatly affected by atmospheric water and oxygen and that these conditions generally lead to DNA loss by aggregation after a few weeks storage. We also confirmed that there is no airtight plastic ware. However, we found that, protected from water and oxygen, DNA primary structure is extremely stable and that the secondary structure is preserved or fully restored upon rehydration, except possibly for small fragments.
METHODS: DNA chain breaks were quantitated by plasmid relaxation or denaturing electrophoresis. DNA denaturation was estimated by hyperchromicity measurements.
RESULTS: From the above observations, we developed a high throughput fully automated process where DNA samples are desiccated in glass inserts which are then enclosed into small laser-sealed capsules under anoxic and anhydrous atmosphere. Traceability is insured by engraving a 2D data matrix code on the capsules. This process has been applied to DNA samples prepared by different techniques from various organisms. Accelerated aging studies established the high stability of these samples.
CONCLUSION: We developed an original procedure which, by ensuring a full and permanent protection of DNA from water and oxygen, allows safe and autonomous room temperature storage with no maintenance and energetic cost.