The DNA test relies on a smartphone instead of lab equipment Supparsorn Wantarnagon/Alamy

It is now possible to use a cheap, lightweight and smartphone-powered DNA detector to identify DNA in blood, urine and other samples, on the spot.

At the moment, testing to identify DNA is usually done in laboratories using expensive, specialised equipment. To make this process faster and cheaper, Ming Chen at the Army Medical University in China and his colleagues developed a portable DNA detector made of 3D-printed parts that attach to a standard smartphone.

The device can detect DNA based on characteristic mutations or short genetic sequences. It costs less than $10 to make, weighs just 60 grams, and takes 80 minutes to produce a result.


DNA fingerprinting

The detector is heated by the smartphone. Samples can be loaded into the detector and mixed with pre-filled chemicals that light up or change colour if there is any DNA that matches. The signals are detected through a lens and a light box and the smartphone displays the result.

Tests showed that the device can detect genetic conditions like alpha- and beta-thalassemia in blood. It also identified people with a gene that makes them more susceptible to alcohol intoxication from swab samples taken from their inner cheeks.

It identified E. coli bacteria in urine, milk and river water. It also identified a bacterium that attacks kiwi fruit plants in ground-up samples of the plant’s leaves.

Read more: Genetic testing companies should not trade science for marketing

Overall, the accuracy of the device was about 97 per cent when compared with standard laboratory methods. The researchers say the device could potentially be modified to identify RNA as well, which would be useful for detecting RNA viruses like the covid-19 virus responsible for the coronavirus pandemic.

Jacqueline Savard at Deakin University in Australia says the technology has the potential to cause unintended consequences if used outside normal clinical settings, because people wouldn’t have access to support and guidance if they test positive for an illness.

Journal reference: Science Advances, DOI: 10.1126/sciadv.aaz7445

We clarified how the device works