Cellular Surveillance: DNA-Based Recording to Monitor and Memorize Biological Events

Continuous monitoring of intra- and extracellular environments, ranging from open fields and rivers to within a single cell, is often limited by costly equipment, labor intensity, or invasive techniques. It may, however, be possible to avoid these issues by developing a monitoring device on a much smaller scale. By applying novel synthetic biology techniques, it is now possible to engineer organisms with refined biorecording capabilities, using DNA as a recording medium on which a cellular “memory” of past events can be written. Through a variety of mechanisms, using recombinases, CRISPR nucleases, base editing, polymerases, and prime editing, intra- and extracellular events can be recorded along with temporal, spatial, and magnitude information. Here, the mechanisms developed for DNA-based biorecording devices so far are assessed and discussed, within the context of the potential future applications of these devices.