Redbud Labs Inc., USA.
University of North Carolina at Chapel Hill, USA.
Lab Chip. 2023 Jan 17;23(2):330-340. doi: 10.1039/d2lc00859a.
Magnetic beads have been widely and successfully used for target enrichment in life science assays. There exists a large variety of commercially available magnetic beads functionalized for specific target capture, as well as options that enable simple surface modifications for custom applications. While magnetic beads are ideal for use in the macrofluidic context of typical laboratory workflows, their performance drops in microfluidic contexts, such as consumables for point-of-care diagnostics. A primary cause is the diffusion-limited analyte transport in these low Reynolds number environments. A new method, BeadPak, uses magnetically actuatable microposts to enhance analyte transport, improving yield of the desired targets. Critical parameters were defined for the operation of this technology and its performance characterized in canonical life-science assays. BeadPak achieved up to 1000× faster capture than a microfluidic chamber relying on diffusion alone, enabled a significant specimen concentration volume reduction, and demonstrated compatibility with a range of biological specimens. The results shown in this work can be extended to other systems that utilize magnetic beads for target capture, concentration, and/or purification.
磁珠在生命科学检测中已被广泛且成功地用于目标富集。目前有大量商业化的磁珠可供选择，这些磁珠具有针对特定目标捕获的功能，并且还可以进行简单的表面修饰，以满足定制应用的需求。虽然磁珠非常适合在典型实验室工作流程的宏观流体环境中使用，但在微流体环境中，例如即时诊断的耗材，其性能会下降。主要原因是在这些低雷诺数环境中，分析物的扩散受到限制。一种新方法 BeadPak 使用可磁驱动的微柱来增强分析物的传输，从而提高所需目标的产量。为该技术的操作定义了关键参数，并在典型的生命科学检测中对其性能进行了表征。BeadPak 的捕获速度比仅依赖扩散的微流控腔快 1000 倍，能够显著减少样本体积，并且与多种生物样本兼容。本工作中展示的结果可以扩展到其他利用磁珠进行目标捕获、浓缩和/或纯化的系统。
