High temperatures and harsh chemicals degrade DNA, but not if it is protected by a skin of silica.

Credit: PHILLIP STÖSSEL

Robert Grass and his colleagues from the Swiss Federal Institute of Technology in Zurich immobilized DNA on charged silica particles and grew a 10-nanometre silica layer on top. The encapsulated DNA was variously subjected to strong ultraviolet radiation, humid 120 °C heat and attack by reactive chemicals. Each time, the molecule could be recovered by dissolving the silica with a weak acid. The DNA remained largely undamaged (much as fossilized DNA is protected in amber) and its sequence could be easily read. The researchers used a 195 °C press to create plastic pills (pictured) containing the protected DNA, which they suggest could be added to consumer goods as high-security barcodes.

Angew. Chem. http://dx.doi.org/10.1002/anie.201208135 (2013)