One-heater flow-through polymerase chain reaction device by heat pipes cooling

Abstract

This study describes a novel microfluidic reactor capable of flow-through polymerase chain reactions (PCR). For one-heater PCR devices in previous studies, comprehensive simulations and experiments for the chip geometry and the heater arrangement were usually needed before the fabrication of the device. In order to improve the flexibility of the one-heater PCR device, two heat pipes with one fan are used to create the requisite temperature regions in our device. With the integration of one heater onto the chip, the high temperature required for the denaturation stage can be generated at the chip center. By arranging the heat pipes on the opposite sides of the chip, the low temperature needed for the annealing stage is easy to regulate. Numerical calculations and thermal measurements have shown that the temperature distribution in the five-temperature-region PCR chip would be suitable for DNA amplification. In order to ensure temperature uniformity at specific reaction regions, the Re of the sample flow is less than 1. When the microchannel width increases and then decreases gradually between the denaturation and annealing regions, the extension region located in the enlarged part of the channel can be observed numerically and experimentally. From the simulations, the residence time at the extension region with the enlarged channel is 4.25 times longer than that without an enlarged channel at a flow rate of 2 ll/min. The treated surfaces of the flow-through microchannel are characterized using the water contact angle, while the effects of the hydrophilicity of the treated polydimethylsiloxane (PDMS) microchannels on PCR efficiency are determined using gel electrophoresis. By increasing the hydrophilicity of the channel surface after immersing the PDMS substrates into Tween 20 (20%) or BSA (1 mg/ml) solutions, efficient amplifications of DNA segments were proved to occur in our chip device. To our knowledge, our group is the first to introduce heat pipes into the cooling module that has been designed for a PCR device. The unique architecture utilized in this flow-through PCR device is well applied to a low-cost PCR system. V C 2015 AIP Publishing LLC.

Review of Experimental Setups for Plasmonic Photocatalytic Reactions

“…Most polymerase chain reaction methods rely on thermal heating and cooling cycles to induce DNA melting and enzyme-driven DNA replication. The treatment solution volume is normally small and is particularly suitable for MOFC reactor processing [207][208][209][210][211][212][213][214][215][216][217]. Plasmonic light-to-heat energy conversion contributed to a breakthrough ultrashort polymerase chain reaction cycle time of 30 cycles in 54 seconds [218].…”

Light Energy Conversion Surface with Gold Dendritic Nanoforests/Si Chip for Plasmonic Polymerase Chain Reaction

“…template DNA before PCR. Lanes 3-15 are PCR products obtained from the Au DNFs/Si chip after 10,15,20,25,30,35,40,45,50,55,60,65, and 70 PCR cycles, respectively. By analysis of the semi-quantitation method, fluorescence intensity measured using ImageJ in Lane 1 was between those in Lanes 5 (25 cycles, 18.75 min) and 6 (30 cycles, 22.5 min).…”

Numerical Investigation of Design and Operating Parameters of Thermal Gradient Continuous-Flow PCR Microreactor Using One Heater

“…The objective of this study is to evaluate the effect that external heat transfer coefficient has on one heater chip. In practice, the average external heat transfer coefficient for PCR system is mostly in the range of 5-15 W/m 2 K [23,33,[36][37][38]. Thus, average external heat transfer coefficients of 5, 10, 12 and 15 W/m 2 K are considered in this study.…”

“…By varying the protrusion length of the invar sheet, different thermal zones can be established on the chip. Chen et al [23] incorporated heat pipes as a cooling system with one heater to build a CF-PCR chip. The heater was integrated to the center of the chip while two heat pipes with a fan were placed on the opposite sides of the chip to produce five temperature zones on it.…”