Human DNA exhaled in our outbreaths, and inhaled by others in their inbreaths, is a little-known form of DNA shedding and exchange, although viral shedding from human outbreaths has become intensely scrutinised during the current pandemic.
In ’93% Human’ Helen Pynor and collaborating scientist Jimmy Breen use a scientific glassware condenser device, which converts gaseous breath into liquid, to capture a shared breath sample which pools as liquid at the base of the device, rendering what is normally imperceptible into visible form.
At a time when the sharing of air with another has become deeply fraught, their performative actions explore the intimacy of our unnoticed exchanges with others, and ‘contamination’ as a necessary condition of being, as they labour to sustain breathing into the device for 10 minutes.
DNA in Pynor and Breen’s combined exhaled breath sample is later extracted, sequenced and the genomic data analysed in Breen’s laboratory. This reveals 93% human DNA, alongside DNA from a range of respiratory tract microbiome species, highlighting the multispecies nature of being ‘human’ and the respiratory tract as site for material exchange between self, human and non-human others, and world.
More broadly, DNA’s propensity to move beyond the cell as an imagined boundary and move into other bodies, the world, and sometimes other genomes, offers a critique of Western understandings of the bounded self and the categorical classification of species.