A 3D-printed oscillatory polymerase chain reaction system using a single heater

Abstract

Nucleic acid amplification is a process that arises in all organisms. Polymerase chain reaction (PCR) is a standard laboratory nucleic acids amplification technology in vitro widely used in medical detection and biometric-related research. This device represents the first demonstration of 3D-printed oscillatory thermocycling within a portable PCR device. This study uses a single Peltier element to create the three temperature regions required for PCR. The overall control system uses an Arduino microcontroller with the advantages of easy development, abundant resources, and easy access to device software design. The sample-driving system integrated with the 3D printed object and the laser-cut acrylic component to achieve the linear reciprocating motion of the sample is conducive to the realisation of the portable design of the device. After system optimisation, the reaction tube moves from the denaturation zone to the aluminum block for cooling, and it moves to the groove of the denaturation zone from the annealing zone to accelerate the sample temperature rise. The time duration reduces from 180 s to 85 s to complete one thermal cycle. Combining the 5 mm instead of 3 mm thickness of the acrylic material and the configuration of the acrylic end exposed in the air creates a more significant temperature difference from 25 °C to 40 °C. Using this oscillatory PCR device, we successfully amplified a 219 bp PCR product of turmeric DNA after 30 thermal cycles within 50 min. The developed PCR device will cost less than $300 USD in our work. Compared with previous works, the cost of this research device is relatively low, and the total volume of the device is quite small. This work should be interesting to persons involved in diagnosing the infectious diseases of viruses and bacteria and identifying the fake healthy food in the low-cost bioreaction chambers in fields and remote areas.