A Radiation Heating-Based Oscillatory Polymerase Chain Reaction System for Detecting Donkey-Hide Gelatin

Abstract Polymerase chain reaction (PCR) is a biochemical technique for copying DNA by repeatedly changing the temperature of nucleic acid samples. In this study, we aim to create an oscillatory PCR system with a short reaction time, which could have significant practical implications. The device uses an electromechanical module with a servo motor and a homemade heating–cooling system that combines a halogen lamp, a Peltier element, a cooling fin, and a blower fan. We code the motor program to control the reaction chamber moving back and forth in the infrared thermal cycling system. The system uses one infrared lamp for heating and one Peltier element/thermal dissipation fins/blower fan for cooling to shorten the overall reaction time of the thermal process. Results show that using the radiant heating and convection cooling method and a micro-sample of 10 μL to perform a PCR, the total time spent is 35 min, which saves about 1 h compared to commercially available PCR instruments. The proposed PCR approach could specifically detect donkey-hide gelatin (DHG) made from donkey skin, offering a rapid and cost-effective solution. Therefore, our device has the advantages of easy manufacturing, low cost, and rapid temperature ramping rate for PCR.