Department of Bioengineering, Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Proc Natl Acad Sci U S A. 2013 Feb 26;110(9):3310-5. doi: 10.1073/pnas.1219639110. Epub 2013 Feb 11.
Miniaturized laboratory-on-chip systems promise rapid, sensitive, and multiplexed detection of biological samples for medical diagnostics, drug discovery, and high-throughput screening. Within miniaturized laboratory-on-chips, static and dynamic droplets of fluids in different immiscible media have been used as individual vessels to perform biochemical reactions and confine the products. Approaches to perform localized heating of these individual subnanoliter droplets can allow for new applications that require parallel, time-, and space-multiplex reactions on a single integrated circuit. Our method positions droplets on an array of individual silicon microwave heaters on chip to precisely control the temperature of droplets-in-air, allowing us to perform biochemical reactions, including DNA melting and detection of single base mismatches. We also demonstrate that ssDNA probe molecules can be placed on heaters in solution, dried, and then rehydrated by ssDNA target molecules in droplets for hybridization and detection. This platform enables many applications in droplets including hybridization of low copy number DNA molecules, lysing of single cells, interrogation of ligand-receptor interactions, and rapid temperature cycling for amplification of DNA molecules.
微流控芯片实验室系统有望实现生物样本的快速、灵敏和多重检测，可用于医学诊断、药物发现和高通量筛选。在微流控芯片实验室中，不同不混溶介质中的静态和动态液滴已被用作单个容器，以进行生化反应并限制产物。对这些单个亚纳升级液滴进行局部加热的方法可以实现新的应用，这些应用需要在单个集成电路上进行并行、时间和空间复用反应。我们的方法将液滴定位在芯片上的单个硅微波加热器阵列上，以精确控制空气中液滴的温度，从而使我们能够进行生化反应，包括 DNA 解链和单碱基错配检测。我们还证明可以将 ssDNA 探针分子置于溶液中的加热器上，干燥，然后通过液滴中的 ssDNA 靶分子再水合以进行杂交和检测。该平台使液滴中的许多应用成为可能，包括低拷贝数 DNA 分子的杂交、单细胞裂解、配体-受体相互作用的检测以及 DNA 分子的快速温度循环扩增。
