A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay

Cheng Yeh Huang, Po Yen Tsai, I. Chin Lee, Hsin-Yun Hsu, Hong Yuan Huang, Shih Kang Fan, Da Jeng Yao, Cheng Hsien Liu, Wen-Syang Hsu*

*Corresponding author for this work

研究成果: Article

16 引文 斯高帕斯(Scopus)

摘要

Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications.

原文English
文章編號011901
期刊Biomicrofluidics
10
發行號1
DOIs
出版狀態Published - 1 一月 2016

指紋 深入研究「A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay」主題。共同形成了獨特的指紋。

  • 引用此

    Huang, C. Y., Tsai, P. Y., Lee, I. C., Hsu, H-Y., Huang, H. Y., Fan, S. K., Yao, D. J., Liu, C. H., & Hsu, W-S. (2016). A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay. Biomicrofluidics, 10(1), [011901]. https://doi.org/10.1063/1.4939942