Synthetic record

One promising application of synthetic biology is engineering diagnostic cell circuits that can detect disease cues in patient samples, or even in vivo. A pair of studies shows such diagnostic cells could be designed to retain and report "memories" of the signals they encounter via transcriptional or epigenetic circuits to enable long-term monitoring of a disease.

In a May study in Nature Biotechnology, a Harvard University team developed a strain of E. coli expressing a synthetic gene circuit that enabled it to sense tetrathionate -- a transient byproduct of inflammation in the gut -- and retain long-term memory of the encounter by stably turning on LacZ production...