Fluorescence detection using smartphone camera for PCR chips

In this paper, we propose a fluorescence detection system using a smartphone camera instead of photodiodes, which is widely used for fluorescence detection of polymerase chain reaction (PCR) chips. Along with the development of smartphones and open platforms, these cameras are superior to photodiodes in terms of performance, cost and size. This recently developed smartphone camera is applied to the fluorescence detection during the DNA amplification process. While the photodiode provides only an average brightness, the fluorescence distribution inside the PCR chips can also be investigated using the camera. Therefore, the cause of unsatisfactory experimental results as well as the degree of amplification of DNA can be determined. In addition to an example of investigating the chamber condition through photographed fluorescence, a curve of change in relative fluorescence intensity is presented according to the number of PCR cycles. The experimental results show that the proposed system can be used for real-time PCR systems.