Spit is powerful stuff. As Kragh-Furbo and Tutton point out, it can disgust, it can cause offence, it can even (as we have seen acutely over the last 18 months) harbour and transmit disease. Spit, however, also holds promise. With the development of biotechnology over the 20th century, there’s now a the capacity to locate in spit the so-called building blocks of life (to employ the kind of rhetoric that Nelkin and Lindee in the DNA Mystique might describe as everyday ‘gene talk’). It’s because of this that when you register as a stem cell donor in the UK, you don’t even need to provide a blood sample. The registries can get everything they need to know about your genetic profile from just your spit. Enter, the flocked swab.
These swabs – you’ll likely have put one up your nose and down your throat to test for COVID in recent weeks – are used to collect cells from your cheek. The swab is packed, sent to a lab and typed, your genetic information stored on a database so you can be included in future searches for patients who need a stem cell transplant. During my current research project, Mix & Match, I spent lots of time at events where smaller charities register people using these swabs. It’s hard to imagine it now, but we’d peel where it says ‘peel here’, allow the registrant to take the swabs, rubbing their inner cheeks for up to three minutes with them. Then we might hold out an envelope, let the registrant slide their swabs into it, and post off the envelope to the registry.
They’re an interesting site for a lot of circulations. What’s to be done with all the single use plastics for example (think of all the lateral flow tests that need to be discarded after use)? The flow of human cells from the mouth, to the swab, via the post, into the lab, where the material is taken out of the swab and tissue-typed. The data, too – when a tissue-type is entered into a registry, and then searchable globally for patients who require transplants. The data may flow far further than the original cells on the swab ever did. And then, prhaps the most incredible flow of all: the cells from one human donated (because of that original decision to swab and register) perhaps even being flown to another country, to be transplanted into somebody else.
(Author: Dr Ros Williams)