Kishi, JocelynSchaus, ThomasGopalkrishnan, NikhilXuan, FengYin, Peng2018-06-272017Kishi, Jocelyn Y., Thomas E. Schaus, Nikhil Gopalkrishnan, Feng Xuan, and Peng Yin. 2017. “Programmable autonomous synthesis of single-stranded DNA.” Nature chemistry 10 (2): 155-164. doi:10.1038/nchem.2872. http://dx.doi.org/10.1038/nchem.2872.http://nrs.harvard.edu/urn-3:HUL.InstRepos:37160361DNA performs diverse functional roles in biology, nanotechnology, and biotechnology, but current methods for autonomously synthesizing arbitrary single-stranded DNA are limited. Here, we introduce the concept of Primer Exchange Reaction (PER) cascades, which grow nascent single-stranded DNA with user-specified sequences following prescribed reaction pathways. PER synthesis happens in a programmable, autonomous, in situ, and environmentally responsive fashion, providing a platform for engineering molecular circuits and devices with a wide range of sensing, monitoring, recording, signal processing, and actuation capabilities. We experimentally demonstrate a nanodevice that transduces the detection of a trigger RNA into the production of a DNAzyme that degrades an independent RNA substrate, a signal amplifier that conditionally synthesizes long fluorescent strands only in the presence of a particular RNA signal, molecular computing circuits that evaluate logic (AND, OR, NOT) combinations of RNA inputs, and a temporal molecular event recorder that records in the PER transcript the order in which distinct RNA inputs are sequentially detected.en-USJournal Article2018-06-2710.1038/nchem.2872