The microfluidic-based, label-free image-guided cell sorter offers a low-cost, high information content, and disposable solution that overcomes many limitations in conventional cell sorters. However, flow confinement for most microfluidic devices is generally only one-dimensional using sheath flow. As a result, the equilibrium distribution of cells spreads beyond the focal plane of commonly used Gaussian laser excitation beams, resulting in a large number of blurred images that hinder subsequent cell sorting based on cell image features. To address this issue, we present a Bessel–Gaussian beam image-guided cell sorter with an ultra-long depth of focus, enabling focused images of >85% of passing cells. This system features label-free sorting capabilities based on features extracted from the output temporal waveform of a photomultiplier tube (PMT) detector. For the sorting of polystyrene beads, SKNO1 leukemia cells, and Scenedesmus green algae, our results indicate a sorting purity of 97%, 97%, and 98%, respectively, showing that the temporal waveforms from the PMT outputs have strong correlations with cell image features. These correlations are also confirmed by off-line reconstructed cell images from a temporal–spatial transformation algorithm tailored to the scanning Bessel–Gaussian beam.

中文翻译：

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具有扫描贝塞尔光束的无标记图像编码微流体细胞分选仪

基于微流体的无标记图像引导细胞分选仪提供了一种低成本、高信息量和一次性解决方案，克服了传统细胞分选仪的许多限制。然而，大多数微流体装置的流动限制通常只是使用鞘流进行一维的。结果，细胞的平衡分布超出了常用的高斯激光激发光束的焦平面，导致大量模糊的图像，阻碍了后续基于细胞图像特征的细胞分选。为了解决这个问题，我们提出了一种具有超长焦深的 Bessel-Gaussian 光束图像引导细胞分选仪，能够对超过 85% 的通过细胞进行聚焦图像。该系统具有基于从光电倍增管 (PMT) 检测器的输出时间波形中提取的特征的无标签分类功能。用于分选聚苯乙烯珠、SKNO1 白血病细胞和Scenedesmus绿藻，我们的结果表明分选纯度分别为 97%、97% 和 98%，表明来自 PMT 输出的时间波形与细胞图像特征具有很强的相关性。这些相关性也通过根据扫描贝塞尔高斯光束定制的时空变换算法的离线重建细胞图像得到证实。