Fig. 2

Verification and quantification of exosomes. Exosomes were precipitated from plasma of a healthy woman, a BC patient and supernatant by the agglutinating agent ExoQuick. Exosomes labeled by ExoRed are visible as red dots under the confocal microscope using 63x magnification with a scale bar presented in the picture (a). The extraction of exosomes from BC patients was also verified by Western blot using antibodies specific for the exosome proteins CD63 and CD81, and the miRNA-associated AGO2 protein. The Western blot shows a representative example of the supernatant, lysed and non-lysed exosomes where AGO2 protein was detected in lysed exosomes and supernatant (b). A further Western blot shows exosomes and supernatant, while in exosomes CD63 and CD81 proteins were identified (c). The box plot compares the exosome levels in the plasma of healthy women (n = 10), HER2-positive patients (n = 78), and TNBC patients (n = 40) as measured by an ELISA coated with CD63 antibodies (d)