Sawa Shuya, Sentoku Mitsuru, Yasuda Kenji
Department of Physics, School of Advanced Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
Micromachines (Basel). 2020 Nov 17;11(11):1011. doi: 10.3390/mi11111011.
Precise and quick measurement of samples' flow velocities is essential for cell sorting timing control and reconstruction of acquired image-analyzed data. We developed a simple technique for the single-shot measurement of flow velocities of particles simultaneously in a microfluidic pathway. The speed was calculated from the difference in the particles' elongation in an acquired image that appeared when two wavelengths of light with different irradiation times were applied. We ran microparticles through an imaging flow cytometer and irradiated two wavelengths of light with different irradiation times simultaneously to those particles. The mixture of the two wavelength transmitted lights was divided into two wavelengths, and the images of the same microparticles for each wavelength were acquired in a single shot. We estimated the velocity from the difference of its elongation divided by the difference of irradiation time by comparing these two images. The distribution of polystyrene beads' velocity was parabolic and highest at the center of the flow channel, consistent with the expected velocity distribution of the laminar flow. Applying the calculated velocity, we also restored the accurate shapes and cross-sectional areas of particles in the images, indicating this simple method for improving of imaging flow cytometry and cell sorter for diagnostic screening of circulating tumor cells.
精确快速地测量样本的流速对于细胞分选定时控制和采集的图像分析数据的重建至关重要。我们开发了一种简单的技术，用于单次测量微流控通道中粒子的流速。速度是根据在应用不同照射时间的两种波长光时采集的图像中粒子伸长的差异来计算的。我们使微粒通过成像流式细胞仪，并同时对这些粒子照射不同照射时间的两种波长光。两种波长透射光的混合光被分成两个波长，并在单次拍摄中获取每个波长下相同微粒的图像。通过比较这两张图像，我们根据其伸长差异除以照射时间差异来估算速度。聚苯乙烯珠粒速度的分布呈抛物线状，在流道中心处最高，这与层流的预期速度分布一致。应用计算出的速度，我们还恢复了图像中粒子的准确形状和横截面积，表明这种简单方法可用于改进成像流式细胞仪和用于循环肿瘤细胞诊断筛查的细胞分选仪。
