@article {Bhan634790, author = {Namita J Bhan and Jonathan Strutz and Joshua Glaser and Reza Kalhor and Edward Boyden and George Church and Konrad Kording and Keith E.J. Tyo}, title = {Recording temporal data onto DNA with minutes resolution}, elocation-id = {634790}, year = {2019}, doi = {10.1101/634790}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Recording biological signals can be difficult in three-dimensional matrices, such as tissue. We present a DNA polymerase-based strategy that records temporal biosignals locally into DNA to be read out later, which could obviate the need to extract information from tissue on the fly. We use a template-independent DNA polymerase, terminal deoxynucleotidyl transferase (TdT) that probabilistically adds dNTPs to single-stranded DNA (ssDNA) substrates without a template. We show that in vitro, the dNTP-incorporation preference of TdT changes with the presence of Co2+, Ca2+, Zn2+ and temperature. Extracting the signal profile over time is possible by examining the dNTP incorporation preference along the length of synthesized ssDNA strands like a molecular ticker tape. We call this TdT-based untemplated recording of temporal local environmental signals (TURTLES). We show that we can determine the time of Co2+ addition to within two minutes over a 60-minute period. Further, we can estimate the rise and fall of an input Co2+ pulse to within five minutes. In silico simulations run based on our in vitro data predict TURTLES can record pulses as short as 1 minute and could record up to 10 pulses with high accuracy. TURTLES has 200-fold better temporal resolution than other DNA-based recording techniques.}, URL = {https://www.biorxiv.org/content/early/2019/05/12/634790}, eprint = {https://www.biorxiv.org/content/early/2019/05/12/634790.full.pdf}, journal = {bioRxiv} }