Quantification of colorimetric isothermal amplification on the smartphone and its open-source app for point-of-care pathogen detection (original) (raw)

The increasing risk of infectious pathogens, especially in the under-developed countries, is demanding the development of point-of-care (POC) nucleic acid testing in the low-resource setting conditions. Here, we describe a methodology for colorimetric quantitative analysis of nucleic acid using an easy-to-build smartphone-based platform, offering low-cost, portability, simplicity in operation, and user-friendliness. The whole system consists of a hand-held box equipped with a smartphone, a film heater, a white LED, a loop-mediated isothermal amplification (LAMP) chip, and a DC converter, and all the processes were powered by a portable battery of 5 V. Upon the amplification of the target gene by an Eriochrome Black T-mediated LAMP reaction, the color of the LAMP reaction was changed from violet to blue that was real-time recorded by a smartphone camera. To keep track of the progress of the color change, we developed a novel mobile app in which a hue value was accepted as an indicato...