In 1999, archaeologists recovered three child mummies from a burial site near the 6,739-metre summit of Llullaillaco, an Andean volcano in Argentina. Frozen, sealed, and remarkably preserved, the bodies offered an unusual opportunity: could modern molecular techniques determine not just what pathogens these children carried, but whether they were actively fighting an infection at the time of death.

A 2012 study from John Jay Collegue of Criminal Justice, took mouth swabs from two of the mummies. Shotgun proteomics identified a profile of inflammatory proteins in one sample consistent with an active bacterial respiratory infection. To confirm the pathogen, researchers extracted DNA from the same swabs using a forensicGEM kit, then sequenced the result.

The sequence matched Mycobacterium, supporting the proteomic finding and providing the first direct evidence of active, rather than merely present, pathogenic infection in a sample of this age.

It is an unusual application for chemistry developed for forensic and research labs, but the underlying requirement is the same one that shows up everywhere else in this campaign: a small, degraded, irreplaceable sample, and a need for clean DNA without the chance to try twice.