Xu Gangwei, Si Huaqing, Jing Fengxiang, Sun Peng, Zhao Dan, Wu Dongping
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China.
Turtle Technology Company Limited, Shanghai 200439, China.
Micromachines (Basel). 2020 Nov 24;11(12):1025. doi: 10.3390/mi11121025.
In this work, a double-deck microfluidic chip was presented for digital PCR application. This chip consists of two reverse-placed micro-patterned polydimethylsiloxane (PDMS) layers between the top and bottom glass substrates. Each micropatterned PDMS layer contains more than 20,000 cylindrical micro-chambers to hold the partitioned droplets. The double-deck designs can double the number of chambers and reagent capacity without changing the planar area of the chip. In addition, carbon black was mixed into the pure PDMS gel to obstruct the passage of fluorescence from the positive chambers between the two layers of the chip. Thus, the fluorescence signal of micro-chambers in different layers of the chip after PCR can be collected without mutual interference. The quantitative capability of the proposed chip was evaluated by measuring a 10-fold serial dilution of the DNA template. A high accuracy of the absolute quantification for nucleic acid with a dynamic range of 10 was demonstrated by this chip in this work. Owing to its characteristics of small planar area, large capacity, and sensitivity, the double-deck microfluidic chip is expected to further promote the extensive applications of digital PCR.
在这项工作中，提出了一种用于数字PCR应用的双层微流控芯片。该芯片由顶部和底部玻璃基板之间的两个反向放置的微图案化聚二甲基硅氧烷（PDMS）层组成。每个微图案化的PDMS层包含超过20,000个圆柱形微腔，用于容纳分隔的液滴。双层设计可以在不改变芯片平面面积的情况下使腔室数量和试剂容量加倍。此外，将炭黑混入纯PDMS凝胶中，以阻止荧光从芯片两层之间的阳性腔室通过。因此，可以在不相互干扰的情况下收集PCR后芯片不同层中微腔的荧光信号。通过测量DNA模板的10倍系列稀释来评估所提出芯片的定量能力。在这项工作中，该芯片证明了在动态范围为10的情况下对核酸进行绝对定量的高精度。由于其平面面积小、容量大、灵敏度高的特点，双层微流控芯片有望进一步推动数字PCR的广泛应用。
