Conventional flow cytometers employ hydrodynamic focusing method to insure detection accuracy by forcing cells go through detected position. However, an increased flow velocity will significantly reduce detection precision due to a fact that cells will deviate center position and are easily silted in choke point. In an effort to overcome this limitation, a two-dimension ultrasonic particle focusing method are presented in this work to enhance the performance of flow cytometer. Two piezoelectric transducers are used to attach to a 250 μm × 250 μm rectangular fused silica flow channel to realize the modification. Finite element model simulation is performed for parametrical analysis and simplifying experiment design. 3 μm polystyrene fluorescent particles are adopted to test focusing effect. One dimension acoustic focusing is achieved at 2.95 MHz with single focusing node as well as 2, 3, 4 nodes focusing near 6, 9, 12 MHz respectively. The 2D focusing particle stream width in two dimensions is less than 10 μm. Results verified that this method is applicable for Jurkat cells. Sample flow maintains its stability without clogging up even at high sample concentration. Focusing still works at flow velocity over 100 μl/min. All these results certify this acoustic particles focusing method can enhance the performance of hydrodynamic flow cytometer by minor modification.

中文翻译：

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二维声聚焦技术提高流体动力流式细胞仪的性能

传统的流式细胞仪采用流体动力聚焦方法，通过迫使细胞穿过检测位置来确保检测精度。但是，由于细胞会偏离中心位置并容易在阻塞点淤塞，因此增加的流速将大大降低检测精度。为了克服这一局限性，本文提出了一种二维超声粒子聚焦方法，以增强流式细胞仪的性能。两个压电换能器用于连接到250μm×250μm的矩形熔融石英流道，以实现修改。进行有限元模型仿真，以进行参数分析并简化实验设计。采用3μm的聚苯乙烯荧光粉测试聚焦效果。在2处实现一维声聚焦。95 MHz，具有单个聚焦节点以及分别在6、9、12 MHz附近聚焦的2、3、4个节点。二维二维聚焦粒子流宽度小于10μm。结果证明该方法适用于Jurkat细胞。即使在高样品浓度下，样品流也能保持其稳定性而不会堵塞。聚焦仍然可以超过100μl/ min的流速进行。所有这些结果证明，这种声学粒子聚焦方法通过较小的改动就可以提高流体动力流式细胞仪的性能。聚焦仍然可以超过100μl/ min的流速进行。所有这些结果证明，这种声学粒子聚焦方法通过较小的改动就可以提高流体动力流式细胞仪的性能。聚焦仍然可以超过100μl/ min的流速进行。所有这些结果证明，这种声学粒子聚焦方法通过较小的改动就可以提高流体动力流式细胞仪的性能。