A simple flow cytometry method improves the detection of phosphatidylserine-exposing extracellular vesicles.
Bottom Line: We show that about 50× more Anx5-positive EVs are detected by FCM when detection is triggered on fluorescence as compared with light scattering.By fluorescence triggering, concentrations of 22 000-30 000 Anx5-positive EVs per μL PFP were determined, using two different flow cytometers.Results from EM suggest that EVs down to 100-150 nm diameter are detected by fluorescence triggering.
Affiliation: Molecular Imaging and NanoBioTechnology, UMR-5248-CBMN CNRS-University of Bordeaux-IPB, Pessac, France.Show MeSH
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Mentions: Next, we focused on the determination of the sensitivity of the FL triggering approach, which can be defined as the minimal number of Anx5-F* molecules needed for detecting one single Anx5-positive EV. The fluorescence intensities of a mixture of MESF-FITC calibration particles containing from 0 to 756 000 MESF were measured by FS triggering (Fig.4A,B), from which a calibration curve relating the number of fluorophores of the particles to their fluorescence intensity was drawn (Fig.4C).
Affiliation: Molecular Imaging and NanoBioTechnology, UMR-5248-CBMN CNRS-University of Bordeaux-IPB, Pessac, France.