Engineers develop portable RAT test

UNSW Sydney biosensing engineers have developed technology to make portable RAT test strips just as accurate as PCR tests carried out in a laboratory.

While lab-based PCR tests take two days to show the COVID-19 virus, the test strips offer rapid, on-the-spot disease detection.

Senior researcher Professor Ewa Goldys, with UNSW’s Graduate School of Biomedical Engineering, said the new technology is like having ‘PCR in your pocket’, and that it opens up possibilities for biomedical and environmental diagnostics in the food industry, agriculture, and biosafety management.

Goldys said: “Not only can we easily detect specific gene sequences in a sample, but, unlike PCR, we can do it at room temperature using a test strip that looks exactly like a well-known RAT Covid test – you already know what to do with it.

“So, no more queuing for that PCR test in the future. Also, the cost is very low – currently less than a few dollars per test.”

Study author Dr Fei Deng adds that the new test strips could expedite rapid response to emerging pathogens such as mosquito-borne or lumpy skin diseases, reveal hotspots of antibiotic resistance or help look for threatened animal species.

“We think we created a new benchmark in biosensing – our gene-based tests will be able to be performed anywhere, any time, by virtually anyone.”

The scientists first made tiny DNA nano-circles containing a short sequence of the target DNA, such as the COVID virus.

The DNA nano-circles and the tested sample were mixed with special proteins that were programmed by the UNSW team to cut DNA of the nano-circles – but only when activated by DNA from the targeted pathogen.

Picture: SA Pathology