A method for typing and analyzing extracellular vesicles secreted by tumor cells and immune cells

Abstract

This invention discloses a method for typing and analyzing extracellular vesicles secreted by tumor cells and immune cells, using tumor cell-derived extracellular vesicles (PD-L1). + EpCAM + ) and extracellular vesicles derived from immune cells (PD-L1) + EpCAM ‑ Based on the different expression levels of surface markers, the PD-L1 protein recognition aptamer PD-L1-L, the EpCAM protein recognition aptamer EpCAM-L, and the molecular beacon Connector were designed. When the DNA probe recognizes extracellular vesicles, the fluorescence of the Cy5-PD-L1-L aptamer from tumor cell-derived extracellular vesicles is quenched, and the fluorescence signal of the Connector is restored, while extracellular vesicles from immune cells show no response, thus enabling typing analysis of the two types of extracellular vesicles. The advantage of this invention is that it uses a dual-aptamer and dual-switch strategy to perform typing analysis of extracellular vesicles from different cell sources and avoids false positive signals caused by single aptamer recognition.

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