Single drop test detects disease in 90 minutes

"We can now detect as little as just a few molecules of DNA in almost any sample such as blood, saliva, or even soil," says Matt Trau. (Credit: iStockphoto)

A single-drop DNA test, which works like a pH test for swimming pools, detects disease and gives a result in 90 minutes.

A new study suggests the test—which has successfully detected viruses, bacteria, fungi, and parasites in humans, crops, and cattle—could be used by health workers or farmers in the field to save lives, time, and money.

“We’ve been able to take what would usually be done with complicated equipment in a centralized laboratory and miniaturize it into a single drop of fluid that farmers, for example, can use to get an almost immediate result in the field,” says Matt Trau, a professor at the Australian Institute for Bioengineeing and Nanotechnology at University of Queensland.

Changing color

The test uses a single drop of liquid that changes color if the test is positive. In its current form, it can be made sensitive enough to detect even the smallest trace amounts of DNA or RNA, and can also scan for multiple pathogens (bacteria, viruses, and other micro-organisms that cause disease) or cancer markers.

“We can now detect as little as just a few molecules of DNA in almost any sample such as blood, saliva, or even soil,” Trau says. “This part is particularly exciting for many future applications.”


The test has already proved accurate in detecting human diseases such as HIV, malaria, tuberculosis, and the H1N1 influenza virus. It also has detected E. coli in water, bovine herpes virus in cattle, and fusarium fungus in crops.

There are virtually no limits for potential uses for the technology, says Jimmy Botella, professor in the School of Agriculture and Food Sciences.

“This new test is especially suited for developing countries, but it will also be very useful for the Australian agricultural and livestock industries as it provides a fast method to detect diseases without the need to send samples to the laboratory.

“We expect that the technology would also be beneficial to the Australian Customs and Quarantine services and the Australian export industry as they could test produce in the packinghouse before shipping.”

Source: University of Queensland