On-the-spot DNA tests could prove invaluable to doctors, farmers, and officials responsible for food safety or environmental monitoring. Now Chinese researchers have created an ultra-portable, smartphone-based DNA testing platform that costs less than $10.
Whether testing blood for the presence of a particular disease-causing pathogen or monitoring the presence of certain microbes in river water, DNA testing generally involves looking for a very tiny amount of genetic material in a much bigger sample. That means the first step includes amplifying the amount of DNA until there is enough of it to be sure of reliably detecting whatever it is you’re looking for.
Probably the most ingenious aspect of the new test is its heating system. Amplifying the DNA signal requires the sample to be kept at specific temperatures so that enzymes needed for the process can do their jobs. Previous attempts to create portable DNA tests have struggled with this and have required mains power or bulky heating elements to achieve this.
The new device, however, uses the smartphone itself to heat the samples. The researchers created an app that forces the phone’s processor to run demanding algorithms that cause it to warm up in a predictable way and transmit heat to the i-chip.