Barred from his lab during lockdown, you might reasonably expect that research by organic chemist Vittorio Saggiomo, of Wageningen University & Research in the Netherlands, would have come to a grinding halt. But Saggiomo is a creative type. Instead, he started wondering if he could use common household appliances to test for Covid-19.
There are currently two main types of test. The gold-standard PCR test works by creating billions of copies of viral genetic material and then detecting them. It’s highly sensitive, but involves precise cycling through a range of temperatures. Tests must be sent off to a lab, and it takes a few days to get the result. The alternative lateral flow tests (LFT) use antibodies to detect fragments of the virus. They’re fast, cheap and easy to use, but not as sensitive.
Ideally, we need a home test that’s both easy to use and sensitive. An excellent candidate is a method called loop-mediated isothermal amplification (Lamp). As with PCR, it works by producing copies of the starting genetic material. But Lamp can be combined with a visual “colour readout” – and its reaction is carried out at a fixed temperature.
However, Lamp still needs fine temperature control, and making and shipping the electronic devices normally needed for this is impractical. Here’s where Saggiomo comes in. He tried wax substances called “phase change materials” that absorb energy as they melt and so maintain a constant temperature. He then constructed a device to house the Lamp reaction tubes and the wax, all encased with used Nespresso coffee machine capsules. Next, he had to find the right way to heat the capsules. After trying the dishwasher, a microwave oven and cups of hot water, Saggiomo settled on a simple pan of simmering water on a stovetop.
The resulting “CoroNaspresso” device, when tested, correctly identified cases of Covid-19. These devices are cheap (about €0.20), easy to make and easy to use. If they were to be mass produced, people would be able to swab for genetic material at home and heat the capsules to get their results. Just don’t get them confused with your regular coffee pods.
This piece is a preview from the Witness section of New Humanist summer 2021. Subscribe today.
