Department of Biomechatronics Engineering, National Pingtung University of Science and Technology , 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
Department of Veterinary Medicine, National Pingtung University of Science and Technology , 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
Biomicrofluidics. 2015 Jan 22;9(1):014107. doi: 10.1063/1.4906505. eCollection 2015 Jan.
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 μl/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.
本研究描述了一种新型的微流控反应器，能够实现高通量聚合酶链反应（PCR）。在之前的研究中，对于单加热器 PCR 设备，通常需要在制造设备之前对芯片几何形状和加热器布置进行全面的模拟和实验。为了提高单加热器 PCR 设备的灵活性，我们在设备中使用了两个带有一个风扇的热管来创建所需的温度区域。通过将一个加热器集成到芯片上，可以在芯片中心产生变性阶段所需的高温。通过在芯片的相对侧布置热管，很容易调节退火阶段所需的低温。数值计算和热测量表明，五温度区 PCR 芯片中的温度分布将适合 DNA 扩增。为了确保特定反应区域的温度均匀性，样品流的 Re 小于 1。当微通道宽度在变性和退火区域之间逐渐增加然后减小时，可以在数值和实验上观察到位于通道放大部分的扩展区域。从模拟结果来看，在流速为 2μl/min 时，具有放大通道的扩展区域的停留时间比没有放大通道的停留时间长 4.25 倍。使用水接触角对微通道的处理表面进行了特征描述，同时通过凝胶电泳确定了处理后的聚二甲基硅氧烷（PDMS）微通道的亲水性对 PCR 效率的影响。通过将 PDMS 基底浸入吐温 20（20%）或 BSA（1mg/ml）溶液中以增加通道表面的亲水性，证明了在我们的芯片设备中可以有效地扩增 DNA 片段。据我们所知，我们小组是第一个将热管引入到专为 PCR 设备设计的冷却模块中的小组。这种高通量 PCR 设备中使用的独特架构非常适用于低成本 PCR 系统。
