The deoxyribonucleic acid (DNA) represents the ‘essence of life’ and contains the most precious information of every individual, such as a person’s ancestry, health conditions, and traits. Although its decoding was successful already 70 years ago, up till now a simple, cost-efficient method has not been developed to safely preserve DNA without perturbations over long periods of time. To date, so-called DNA banking is accessible primarily to wealthy consumers, because the service provided by more than 100 DNA banking companies and organizations worldwide, that includes the extraction of the genomic DNA from blood or saliva samples as well as its storage for more than 50 years under laboratory cryoconditions, i.e. in the range of -80 °C to -164 °C, can cost between a hundred and a thousand dollars.
In order to make DNA banking accessible to everyone and to become independent of specialized equipment as well as the expensive maintenance at ultra-low temperature cryopreservation, the Zhu group and we have developed a novel method of in situ cryosilicification of whole blood cells (see Figure) . Our simple approach ‘freezes’ whole blood cells in amorphous silica in such a way that these cryosilicified samples are extremely robust against external stressors such as aggressive radical oxygen species or ultraviolet radiation, and also feature long-term stability under humid conditions at elevated temperatures. To verify that these clearly fulfill the essential criteria for a safe, long-term DNA preservation, their performance was evaluated by developing two different DNA banking formats: first, filter paper-based blood cards and second, 3D-printed artefacts. Both exhibited an excellent preservation of the DNA without perturbations at room temperature for extrapolated periods of time of up to thousand years, satisfying different needs of society, i.e. either very little storage capacities in a book-size format at only 0.5$/person or the opportunity to create customized 3D artefacts.
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