Cells can now keep a diary: a new method archives a cell's own messages, so scientists can read what it did days ago

Biologists have always faced a frustrating limit: measuring a cell destroys the moment, so you learn what its genes are doing now, never what they were doing yesterday. Researchers at ETH Zurich, in Basel, Switzerland, have built a way around it. Their system, called Recordanelles, persuades a cell to store copies of its own RNA — the working messages its genes send — in a protective film around its mitochondria, the cell's power stations. Several thousand messages per cell can be archived over several days, then read back later like a flight recorder. Published in Nature Biotechnology, the method could crack a problem that haunts cancer care: a few 'persister' cells survive chemotherapy by quietly changing their behaviour, then seed the cancer's return. Until now their trick was invisible, because by the time anyone looked, the moment had passed. A cell that keeps a diary cannot hide its past so easily.

SDG 9 · Industry, innovation and infrastructure — Mechanism: tech innovation