Small-Size Polymerase Chain Reaction Device with Improved Heat Transfer and Combined Feedforward/Feedback Control Strategy

Abstract

We report improvements on the heat transfer and on the control strategy of a thermal cycler implemented on a novel device for performing a fast polymerase chain reaction (PCR). The reduction of the thermal mass of the sample holder and the direct contact with the sample allow for a significant reduction of the transition times, while the hybrid feedforward/feedback controller can rely on inexpensive components (actuators, sensors, processor) and still achieve minimal over/undershooting and good temperature stability. The design of the device has been improved by performing transient heat conduction analysis on the highly heat-conductive sample holder and on the solid metal body of the device which rapidly dissipates the excess heat produced during the thermal cycling. In the current setup, the sample holder hosts nine 1 μL samples covered with mineral oil, which can be simultaneously read in real time by the detection module designed in-house and installed on the device. An increase in speed of the PCR amplification was achieved with a reduction of the transition time of 63.8% when compared against a commercial real-time PCR machine. Our work shows that a complete, stand-alone, and ready-to-use quantitative PCR instrument can be fabricated from inexpensive and easily available components and it can achieve fast thermal cycling thanks to a hybrid control strategy.

Rapid Identification of SARS-CoV-2 Variants of Concern Using a Portable peakPCR Platform

“…To further simplify, decentralize, and speed up the process of VOC identification, we transformed our assay to a portable and inexpensive qPCR device, named peakPCR . 16 The device can complete up to 20 RT-qPCR reactions in less than 40 min. Important characteristics of peak PCR are the relatively low cost of production and the simplicity of usage.…”

Molecular Detection of Feline Coronavirus Based on Recombinase Polymerase Amplification Assay

“…One research group optimized the heat transfer to achieve fast thermal cycling with the use of a sample holder that quickly dissipated excess heat due to its high thermal conductivity. The significant reduction of the transition times (68% compared to commercial real-time PCR) leads to an increased speed of amplification [58]. A different approach to speed up PCR is the use of induction heating [59].…”

An LED-Driven AuNPs-PDMS Microfluidic Chip and Integrated Device for the Detection of Digital Loop-Mediated Isothermal DNA Amplification

“…The temperature profile indicated that the chip temperature can reach ~62 °C within 17 s and then fluctuated slightly between 61.8 and 63.6 °C, and this is an acceptable fluctuation range for LAMP amplification. Compared with the contact-type hot-plate heating method widely used in commercial instruments, this non-contact LED-driven heating solution no longer requires the hot cover for reducing the temperature difference between the hot plate and the chip [29]. This is because AuNPs can efficiently and directly convert the energy from the NIR-LED source into heat of the PDMS film.…”

“…During droplet generation, the flow rate of the oil phase and the LAMP reagent was 12 and 6 μL/min, respectively, so it takes ~4 min to complete sample segmentation of 20 μL of LAMP reagent. The droplet size profile is of great value for characterizing the sample Compared with the contact-type hot-plate heating method widely used in commercial instruments, this non-contact LED-driven heating solution no longer requires the hot cover for reducing the temperature difference between the hot plate and the chip [29]. This is because AuNPs can efficiently and directly convert the energy from the NIR-LED source into heat of the PDMS film.…”