Imaging of fast-moving single cells with adaptive single pixel detection

开发一种能够在单细胞水平上快速检测细胞群的非靶向技术是面临各种挑战的下一代技术。因此，我们的愿景是，可以根据以下设计标准开发一种便于无标记多组分析的质谱系统：与低通量方法相匹配的生化覆盖范围（约500种蛋白质，200种代谢物和300种脂质）因此，我们提出了一种新的设计，通过使用由流动聚焦机制产生的含有细胞的液滴来解决这些挑战，液滴中的化学消化之后是皮秒共振红外激光蒸发，然后对产生的气态有机离子进行质谱分析。需要解决的一个主要研究问题是进入的细胞/生物的准确蒸发，预计其速度至少为1m/s，并且需要验证液滴的含量以避免“假阳性”，因此需要实时的空间信息。因此，将构建一种能够以至少每秒10^4帧的速率捕获移动细胞的空间信息的超快成像装置，以促进后续的质谱分析，并在单个细胞水平上提供额外的生物物理信息。相对于昂贵的阵列探测器，单像素检测（SPD）为当前的问题提供了一个可靠的替代解决方案，而阵列探测器通常具有有限的可用性和不同的应用范围的性能特征。

Development of an untargeted technique capable of rapidly detecting cell populations at a single cell level is a sought after next-generation technology that faces various challenges.It is thus our vision that a mass spectrometric system that facilitates unlabelled, multi-omic analysis can be developed with the following design criteria: 1. the biochemical coverage to match the power of low throughput methods (~500 proteins, 200 metabolites and 300 lipid species)2. analysis of up to 10,000 mammalian cells (or other single-cell organisms)/second We have thus proposed a new design addressing these challenges by using cell-containing liquid droplets produced by a flow focusing mechanism, and the in-droplet chemical digestion is followed by picosecond resonant infrared laser evaporation prior to mass spectrometric analysis of the produced gaseous organic ions. A major research problem to be solved is the accurate evaporation of the incoming cells/organisms which is expected to travel at a speed of at least 1m/s and the content of the droplets needs to be verified to avoid 'false positives', hence spatial information in real-time is needed.An ultrafast imaging set-up capable of capturing the spatial information of the moving cells at a rate that is at least on the order of 10^4 frames per second will thus be constructed to facilitate the succeeding mass spectrometric analysis and to provide additional biophysical information at a single cell level. Instead of costly array detectors that generally have limited availability and differing performance characteristics across the application spectrum, single pixel detection (SPD) offers a robust alternative solution for the problem at hand.