Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG-1), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, 76344, Germany.
IBM Research Europe, Säumerstrasse 4, Ruschlikon, 8803, Switzerland.
Small. 2020 Dec;16(49):e2005476. doi: 10.1002/smll.202005476. Epub 2020 Nov 17.
Nucleic acid hybridization reactions play an important role in many (bio)chemical fields, for example, for the development of portable point-of-care diagnostics, and often such applications require nucleic acid-based reaction systems that ideally run without enzymes under isothermal conditions. The use of novel capillary-driven microfluidic chips to perform two isothermal nucleic acid hybridization reactions, the simple opening of molecular beacon structures and the complex reaction cascade of a clamped-hybridization chain reaction (C-HCR), is reported here. For this purpose, reagents are arranged in a self-coalescence module (SCM) of a passive silicon microfluidic chip using inkjet spotting. The SCM occupies a footprint of ≈7 mm of a ≈0.4 × 2 cm microfluidic chip. By means of fluorophore-labeled DNA probes, the hybridization reactions can be analyzed in just ≈2 min and using only ≈3 µL of the sample. Furthermore, the SCM chip offers a variety of reagent delivery options, allowing, for example, the influence of the initiator concentration on the kinetics of C-HCR to be investigated systematically with minimal sample and time requirements. These results suggest that self-powered microfluidic chips equipped with a SCM provide a powerful platform for performing and investigating complex reaction systems.
核酸杂交反应在许多（生物）化学领域中发挥着重要作用，例如用于开发便携式即时诊断，而此类应用通常需要在等温条件下无需酶即可运行的基于核酸的反应系统。本文报道了使用新型毛细管驱动微流控芯片来进行两种等温核酸杂交反应，即简单地打开分子信标结构和复杂的夹式杂交链式反应（C-HCR）反应级联。为此，试剂在被动硅微流控芯片的自聚结模块（SCM）中使用喷墨点样进行排列。SCM 占据了 ≈0.4×2cm 微流控芯片 ≈7mm 的占地面积。通过荧光标记的 DNA 探针，仅需 ≈3µL 的样本即可在 ≈2 分钟内分析杂交反应。此外，SCM 芯片提供了多种试剂输送选项，例如可以在最小的样本和时间要求下，系统地研究引发剂浓度对 C-HCR 动力学的影响。这些结果表明，配备 SCM 的自供电微流控芯片为执行和研究复杂反应系统提供了强大的平台。
