Uddin Rokon, Kinahan David, Ducrée Jens, Boisen Anja
Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark.
Department of Mechanical and Manufacturing Engineering, Dublin City University, Glasnevin, Dublin 9, Ireland.
Biomicrofluidics. 2021 Nov 9;15(6):064102. doi: 10.1063/5.0066128. eCollection 2021 Dec.
In this paper, we present a centrifugal microfluidic concept employing event-triggered valving for automated extraction of metered plasma and peripheral blood mononuclear cells (PBMCs). This "lab-on-a-disk" system has been developed for retrieving different density layers from a liquid column by "overflowing" the layers sequentially using the pressure exerted by a density-gradient liquid. Defined volumes of plasma and PBMCs were efficiently forwarded into designated microfluidic chambers as a sample preparation step prior to further downstream processing. Furthermore, the extracted PBMCs were counted directly on-disk using an automated optical unit by object-based image analysis, thus eliminating the requirement for the post-processing of the extracted PBMCs. This study is a direct continuation of our previous work where we demonstrated combined on-disk detection of C-reactive protein and quantification of PBMCs following on-disk extraction of plasma and PBMCs from a single blood sample using a centrifugo-pneumatic valving mechanism. However, the former valving technique featured limited PBMC extraction efficiency. Here, integrating the novel concept along with event-triggered valving mechanism, we eliminated the occurrence of a specific microfluidic effect, which led us to increase PBMC extraction efficiency to 88%. This extraction method has the potential to be utilized for efficiently separating multiple density layers from a liquid sample in relevant biomedical applications.
在本文中，我们提出了一种离心微流控概念，该概念采用事件触发阀控技术来自动提取定量的血浆和外周血单核细胞（PBMC）。这种“盘上实验室”系统是为通过利用密度梯度液体施加的压力依次“溢出”各层，从液柱中检索不同密度层而开发的。在进一步的下游处理之前，作为样品制备步骤，将确定体积的血浆和PBMC有效地转移到指定的微流控腔室中。此外，使用基于对象的图像分析，通过自动光学单元直接在盘上对提取的PBMC进行计数，从而消除了对提取的PBMC进行后处理的需求。本研究是我们先前工作的直接延续，在先前的工作中，我们展示了使用离心气动阀控机制从单个血样中盘上提取血浆和PBMC后，对C反应蛋白进行盘上联合检测以及对PBMC进行定量。然而，前一种阀控技术的PBMC提取效率有限。在这里，将这种新颖的概念与事件触发阀控机制相结合，我们消除了一种特定微流控效应的发生，这使我们将PBMC提取效率提高到了88%。这种提取方法有潜力在相关生物医学应用中用于从液体样品中高效分离多个密度层。
