The invention relates to an improved purification environment and pure bacterium source
extracellular vesicle method, and relates to the technical field of
biology, the method comprises the following steps: S1, obtaining a first crude extraction
extracellular vesicle sample, carrying out exploratory multi-layer
density gradient ultracentrifugation on the first sample, and carrying out characterization analysis on each centrifuged component, to determine an enrichment zone of
extracellular vesicles; and S2, obtaining an
extracellular vesicle sample of a second crude extraction homologous with the
extracellular vesicle sample of the first crude extraction, constructing an optimized simplified
density gradient according to the enrichment regions determined in the step S1, and carrying out optimized simplified
density gradient ultracentrifugation on the second sample to collect and purify the
extracellular vesicles. According to the method disclosed by the invention, a standardized scheme is established for a specific sample through two steps of exploratory purification and purification after optimization, and enrichment regions of the
extracellular vesicles are determined by adopting an identification method combining a transmission
electron microscope and nanoflow
cytometry, so that the
repeatability of a purification result is improved.