Extracellular Vesicles (EVs) can be used as biomarkers in diseases like cancer, as their lineage of origin and molecular composition depend on the presence of cancer cells. Recognition of tumor-derived EVs (tdEVs) from other particles and EVs in body fluids requires characterization of single EVs to exploit their biomarker potential. We present here a new method based on synchronized Rayleigh and Raman light scattering from a single laser beam, which optically traps single EVs. Rapidly measured sequences of the Rayleigh scattering amplitude show precisely when an individual EV is trapped and the synchronously acquired Raman spectrum labels every time interval with chemical information. Raman spectra of many single EVs can thus be acquired with great fidelity in an automated manner by blocking the laser beam at regular time intervals. This new method enables single EV characterization from fluids at the single particle level.

中文翻译：

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同步瑞利和拉曼散射用于表征单个光学捕获的细胞外囊泡。

细胞外囊泡（EVs）可以用作癌症等疾病的生物标志物，因为它们的起源和分子组成取决于癌细胞的存在。从体液中的其他颗粒和电动汽车中识别肿瘤衍生电动汽车（tdEV），需要对单个电动汽车进行表征，以开发其生物标志物的潜力。我们在这里提出了一种基于同步雷利和拉曼光从单个激光束散射的新方法，该光学方法可以捕获单个电动汽车。快速捕获的瑞利散射幅度序列可精确显示何时捕获了单个电动汽车，并在每个时间间隔内通过化学信息同步采集拉曼光谱标记。通过以规则的时间间隔阻挡激光束，可以以高保真度自动获取许多单个电动汽车的拉曼光谱。