Balsam Joshua, Bruck Hugh Alan, Rasooly Avraham
Division of Biology, Office of Science and Engineering, FDA, Silver Spring, MD, 20993, USA.
Methods Mol Biol. 2015;1256:139-53. doi: 10.1007/978-1-4939-2172-0_10.
Flow cytometry is used for cell counting and analysis in numerous clinical and environmental applications. However flow cytometry is not used in mHealth mainly because current flow cytometers are large, expensive, power-intensive devices designed to operate in a laboratory. Their design results in a lack of portability and makes them unsuitable for mHealth applications. Another limitation of current technology is the low volumetric throughput rates that are not suitable for rapid detection of rare cells.To address these limitations, we describe here a novel, low-cost, mobile flow cytometer based on wide-field imaging with a webcam for large volume and high throughput fluorescence detection of rare cells as a simulation for circulating tumor cells (CTCs) detection. The mobile flow cytometer uses a commercially available webcam capable of 187 frames per second video capture at a resolution of 320 × 240 pixels. For fluorescence detection, a 1 W 450 nm blue laser is used for excitation of Syto-9 fluorescently stained cells detected at 535 nm. A wide-field flow cell was developed for large volume analysis that allows for the linear velocity of target cells to be lower than in conventional hydrodynamic focusing flow cells typically used in cytometry. The mobile flow cytometer was found to be capable of detecting low concentrations at flow rates of 500 μL/min, suitable for rare cell detection in large volumes. The simplicity and low cost of this device suggests that it may have a potential clinical use for mHealth flow cytometry for resource-poor settings associated with global health.
流式细胞术在众多临床和环境应用中用于细胞计数和分析。然而，流式细胞术未用于移动医疗领域，主要是因为当前的流式细胞仪体积大、价格昂贵且功耗高，是设计用于在实验室中操作的设备。其设计导致缺乏便携性，使其不适用于移动医疗应用。当前技术的另一个局限性是低体积通量率，不适用于罕见细胞的快速检测。为了解决这些局限性，我们在此描述一种新型的、低成本的移动流式细胞仪，它基于宽场成像，配备网络摄像头，用于对罕见细胞进行大体积和高通量荧光检测，作为循环肿瘤细胞（CTC）检测的模拟。该移动流式细胞仪使用一款市售网络摄像头，能够以320×240像素的分辨率每秒捕获187帧视频。对于荧光检测，使用1W 450nm蓝色激光激发在535nm处检测的用Syto-9荧光染色的细胞。开发了一种用于大体积分析的宽场流动池，其允许靶细胞的线速度低于通常用于细胞术的传统流体动力聚焦流动池。发现该移动流式细胞仪能够在500μL/min的流速下检测低浓度，适用于大体积中的罕见细胞检测。该设备的简单性和低成本表明，它可能在与全球健康相关的资源匮乏环境中的移动医疗流式细胞术方面具有潜在的临床用途。
