Development and Application of Portable Neutrophil Chemotaxis Research System

In order to solve the problem that cell chemotaxis research requires the use of relatively expensive microscope for continuous and timed image collection and analysis of cell chemotaxis, ImageJ software is required to manually track the cell movement path. A portable cell chemotaxis migration analysis system based on universal serial bus (USB) microscope was designed. The hardware of the analysis system consists of computer, USB microscope, microfluidic chip, temperature control unit and microscope support. It was used to investigate cell chemotaxis through image acquisition, image processing and various analysis algorithms. In the experiment, first of all, 90 cell images were collected within 15 min at an interval of 10 s by using USB microscope. Then the integrated software based on National Instruments' (NI) IMAQ Vision software package was used to complete the image processing. On the one hand, the width pixels of the first and last cell images were divided into 10 parts, and cell partition count and digital score were used to preliminarily analyze the chemotaxis of cells. On the other hand, the central coordinates of the cells can be recognized and the cell motion trace can be tracked by combining the minimum distance method, and then the chemotaxis index, total migration distance, movement velocity and gradient displacement of the cells can be calculated. The performance of the portable cell chemotaxis detection system was verified by collecting and analyzing the moving images of neutrophils. At the same time, the effect of different glucose concentrations on the chemotaxis performance of neutrophils was investigated by using the system. The results show that the portable chemotactic migration analysis system can automatically analyze the cell migration index, the portable cell chemotaxis detection system improves the integration and portability of cell chemotaxis research.

为解决现有细胞趋化性研究中的如下问题：需使用价格相对高昂的显微镜开展连续定时图像采集以进行细胞趋化性分析，且需借助ImageJ软件手动追踪细胞运动路径，本研究设计了一套基于通用串行总线（USB）显微镜的便携式细胞趋化迁移分析系统。该分析系统的硬件由计算机、USB显微镜、微流控芯片、温控单元及显微镜支架组成，可通过图像采集、图像处理及各类分析算法开展细胞趋化性研究。实验阶段，首先使用USB显微镜以10秒为间隔，在15分钟内采集了90张细胞图像；随后基于美国国家仪器（NI）的IMAQ Vision软件开发包搭建的集成软件完成图像处理工作。一方面，将首末两张细胞图像的宽度像素均分为10份，通过细胞分区计数与数值评分对细胞趋化性进行初步分析；另一方面，结合最小距离法可识别细胞的中心坐标并追踪细胞运动轨迹，进而计算得到细胞的趋化指数、总迁移距离、运动速度及梯度位移。通过采集并分析中性粒细胞的运动图像，验证了该便携式细胞趋化迁移分析系统的性能；同时借助该系统探究了不同葡萄糖浓度对中性粒细胞趋化性能的影响。实验结果表明，该便携式趋化迁移分析系统可自动分析细胞迁移相关指标，且有效提升了细胞趋化性研究的集成度与便携性。