Department of Mechanical Engineering, Konkuk University, Seoul, 05029, Republic of Korea.
Lab Chip. 2018 Mar 13;18(6):915-922. doi: 10.1039/c7lc01328k.
We demonstrate a microfiltration chip that separates blood plasma by using water-head-driven pulsatile pressures rather than any external equipment and use it for on-chip amplification of nucleic acids. The chip generates pulsatile pressures to significantly reduce filter clogging without hemolysis, and consists of an oscillator, a plasma-extraction pump, and filter units. The oscillator autonomously converts constant water-head pressure to pulsatile pressure, and the pump uses the pulsatile pressure to extract plasma through the filter. Because the pulsatile pressure can periodically clear blood cells from the filter surface, filter clogging can be effectively reduced. In this way, we achieve plasma extraction with 100% purity and 90% plasma recovery at 15% hematocrit. During a 10 min period, the volume of plasma extracted was 43 μL out of a 243 μL extraction volume at 15% hematocrit. We also studied the influence of the pore size and diameter of the filter, blood loading volume, oscillation period, and hematocrit level on the filtration performance. To demonstrate the utility of our chip for point-of-care testing (POCT) applications, we successfully implemented on-chip amplification of a nucleic acid (miDNA21) in plasma filtered from blood. We expect our chip to be useful not only for POCT applications but also for other bench-top analysis tools using blood plasma.
我们展示了一种微滤芯片，它利用水头驱动的脉动压力而非任何外部设备来分离血浆，并将其用于在芯片上对核酸进行扩增。该芯片产生脉动压力以在不发生溶血的情况下显著减少过滤器堵塞，它由振荡器、血浆提取泵和过滤单元组成。振荡器自主地将恒定水头压力转换为脉动压力，泵利用脉动压力通过过滤器提取血浆。由于脉动压力可以周期性地从过滤器表面清除血细胞，因此可以有效地减少过滤器堵塞。这样，我们以 15%的红细胞比容实现了 100%纯度和 90%的血浆回收率的血浆提取。在 10 分钟的时间内，在 15%的红细胞比容下，从 243 μL 的提取体积中提取了 43 μL 的血浆。我们还研究了孔径和过滤器直径、血液加载量、振荡周期和红细胞比容水平对过滤性能的影响。为了展示我们的芯片在即时检测（POCT）应用中的实用性，我们成功地实现了从过滤的血浆中对核酸（miDNA21）的芯片上扩增。我们预计我们的芯片不仅在 POCT 应用中有用，而且在其他使用血浆的台式分析工具中也有用。
