Water-cooling-based and low-cost qPCR device for rapid nucleic acid analysis

Real-time quantitative PCR (qPCR) is a sought-after method for quantifying nucleic acids. A series of commercial instruments based on qPCR has been developed and applied to detect several diseases. However, commercial instruments have some limitations in terms of cost, bulk, and efficiency. Herein, we proposed a novel qPCR device using water-cooling technology to shorten the period of the PCR reaction. The device was made of an amplification module with a novelty water-cooling-based PCR chip, a custom-made fluorescence detection module, and a control module based on economical off-the-shelf electronics. All these modules were assembled in a 3D-printed frame with a size of 11cm × 9.7cm × 8.9cm and a weight of 0.5kg. With the help of water-cooling technology, the total time required to complete a PCR reaction was shortened, with a maximum cooling rate of 12 ℃/s, which is much faster than the rate of conventional cooling methods. Compared with commercial qPCR instruments, our device's cost, efficiency, and portability have been significantly optimized. To test the proposed device, a qPCR experiment was successfully performed with cDNA of Vesicular stomatitis virus at concentrations ranging from 0.005μg/mL to 50μg/mL.