Infrared temperature control system for a completely noncontact polymerase chain reaction in microfluidic chips
Infrared temperature control system for a completely noncontact polymerase chain reaction in microfluidic chips
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DOI：
10.1021/ac0613277
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发表时间：
2007-02-15
影响因子：
7.4
通讯作者：
Landers, James P.
中科院分区：
文献类型：
--
作者：
Roper, Michael G.;Easley, Christopher J.;Landers, James P.
本文介绍了一种用于玻璃微流控芯片中DNA聚合酶链式反应（PCR）扩增的完全非接触式温度控制系统。将红外（IR）敏感高温计相对于插入到550-nL PCR室中的热电偶进行校准，并用于在分别由钨灯和对流空气源诱导的加热和冷却期间监测PCR室上方的玻璃表面的温度。在溶液和表面的最大加热速率之间观察到小于1 s的时间滞后，表明快速达到热平衡。此外，使用一维传热模型证实了时间滞后，该模型提供了对导致时间滞后的设备和环境的特性的深入了解。反过来，这些知识将允许未来根据特定应用定制设备。为了减少用热电偶校准高温计的需要，通过感测两种溶液（水和水溶性溶剂）的沸腾，并将高温计输出电压与这些溶液的已知沸点进行比较，来完成高温计的片上校准。“沸点校准”是成功的，如随后基于芯片的B的211-bp片段的IR-PCR扩增所指示的。炭疽菌基因组在一个房间缩小超过一个热电偶的尺寸。为了提高加热速率，将抛物面金镜放置在微流控芯片上方，这将PCR扩增加速到18.8分钟，用于30个循环，三温度方案。
A completely noncontact temperature system is described for amplification of DNA via the polymerase chain reaction (PCR) in glass microfluidic chips. An infrared (IR)-sensitive pyrometer was calibrated against a thermocouple inserted into a 550-nL PCR chamber and used to monitor the temperature of the glass surface above the PCR chamber during heating and cooling induced by a tungsten lamp and convective air source, respectively. A time lag of less than 1 s was observed between maximum heating rates of the solution and surface, indicating that thermal equilibrium was attained rapidly. Moreover, the time lag was corroborated using a one-dimensional heat-transfer model, which provided insight into the characteristics of the device and environment that caused the time lag. This knowledge will, in turn, allow for future tailoring of the devices to specific applications. To alleviate the need for calibrating the pyrometer with a thermocouple, the on-chip calibration of pyrometer was accomplished by sensing the boiling of two solutions, water and an azeotrope, and comparing the pyrometer output voltage against the known boiling points of these solutions. The "boiling point calibration" was successful as indicated by the subsequent chip-based IR-PCR amplification of a 211-bp fragment of the B. anthracis genome in a chamber reduced beyond the dimensions of a thermocouple. To improve the heating rates, a parabolic gold mirror was positioned above the microfluidic chip, which expedited PCR amplification to 18.8 min for a 30-cycle, three-temperature protocol.