Biomicrofluidics. 2010 Jun 15;4(2):024110. doi: 10.1063/1.3380598.
Where engineering meets biological protocol. One basic requirement is to reliably and accurately know the distribution and number of biological cells being dispensed. In this study, a novel optical counting technique to efficiently quantify the number of cells flowing into a microtube is presented. REH, B-lymphoid precursor leukemia, are stained with a fluorescent dye and frames of moving cells are recorded using a charge coupled device (CCD) camera. The basic principle is to calculate the total fluorescence intensity of the image and to divide it by the average intensity of a single cell. This method allows counting the number of cells with an uncertainty +/-5%, which compares favorably to the standard biological methodology, based on the manual Trypan Blue assay, which is destructive to the cells and presents an uncertainty in the order of 20%. The use of a microdevice for vertical hydrodynamic focusing, which can reduce the background noise of out of focus cells by concentrating the cells in a thin layer, has further improved the technique. Computational fluid dynamics (CFD) simulation and confocal laser scanning microscopy images have shown an 82% reduction in the vertical displacement of the cells. For the flow rates imposed during this study, a throughput of 100-200 cellss is achieved.
工程学与生物协议的交汇。一个基本要求是可靠且准确地了解分配和分配的生物细胞的分布和数量。在这项研究中，提出了一种新颖的光学计数技术，可有效地量化流入微管的细胞数量。REH，B 淋巴细胞前体白血病，用荧光染料染色，并使用电荷耦合器件（CCD）相机记录移动细胞的帧。基本原理是计算图像的总荧光强度，并将其除以单个细胞的平均强度。该方法允许以不确定度 +/-5％计数细胞的数量，与基于手动台盼蓝测定法的标准生物学方法相比具有优势，该方法对细胞具有破坏性，并且不确定性约为 20％。使用微器件进行垂直流体动力学聚焦，可以通过将细胞集中在薄层中来减少离焦细胞的背景噪声，从而进一步改善了该技术。计算流体动力学（CFD）模拟和共焦激光扫描显微镜图像显示，细胞的垂直位移减少了 82％。对于在此研究期间施加的流速，可实现 100-200 个细胞的吞吐量。
