Animal and human DNA can be collected from the air in a room, scientists have found for the first time.
The technology has the potential to revolutionise the study of elusive animals, contagious diseases, like Covid-19, and forensics.
For example, if a criminal is suspected to have passed through a crime scene, analysing the air could reveal their DNA and therefore, their identity.
Air sucked from a room and pumped through an ultra-fine filter was able to capture DNA shed by a person’s body, called environmental DNA (eDNA).
Environmental DNA has previously been detected in water, soil and snow and used as a way of studying fish, animals and invasive species.
Dr Elizabeth Clare, a senior lecturer at Queen Mary University of London set about determining if eDNA can be filtered from the air.
The study, published in the journal PeerJ, found naked mole-rat DNA from the air of their lab-based burrows and also the room they are housed in.
So-called ‘AirDNA’ was extracted from the filters and successfully sequenced.
Human DNA from the mole-rats’ carers was also identified by the technology, which the researchers say was a surprise but reveals the sensitivity of the technique.
Researchers believe the human DNA is from the carers of the naked mole-rats, despite these people spending far less time in the room than the animals.
Dr Clare said: ‘Here we provide the first published evidence to show that animal eDNA can be collected from air, opening up further opportunities for investigating animal communities in hard to reach environments such as caves and burrows.’
She adds it ‘opens up some interesting questions’ about how the technology could be used in forensics or archaeology.
For example, if a criminal is suspected to have passed through a crime scene, analysing the air could reveal their DNA and therefore, their identity.
Also, studying the air of a tomb may be a way to obtain DNA samples of long-dead mummies or skeletons.
But the main use, Dr Clare believes, is in the study of hard-to-reach and shy species.
The emerging technology relies on sucking the air in a room into a filter, and this, Dr Clare says, means it may be harder to obtain DNA from larger room, limiting the scope of the technique as the DNA will be so heavily diluted.