“Dr. Stadler’s lab and others around the world are trying to turn cells into their own historians, as she and her colleagues described in the journal Nature Reviews Genetics on Monday. Their engineered cells can insert distinctive bits of genetic material into their DNA. As the cells divide, those genetic bits turn into distinctive bar codes.

The technology is also allowing cells to create a genetic record when they experience a notable event, such as receiving a signal from other cells or making a particular protein.

Dr. Schier speculated that doctors might even someday inject sentinel cells into our bodies to track our changing health. ‘I feel kind of sick now — did I have an infection three months ago? Did I have mercury poisoning seven months ago?’ Dr. Schier said. The answers could be found in the cellular history recorded by sentinel cells.”

From New York Times.