Figure 2. Purification of macrophage-, epithelia- and neutrophil- derived exosomes from total BALF-exosomes from ALI-mice. The isolated BALF-exosomes were further purified into macrophage-, epithelia- and neutrophil- derived exosomes, based on differential expression of precursor cell markers. The purification strategy included size less than 500nm and being positive for specific precursor cell markers. (A) Flow chart for macrophage-derived exosomes: positive for both CD11c and F4/80. (B) Flow chart for epithelia: positive for EpCAM. (C) Flow chart for neutrophils: positive for both CD11b and Ly6G. (D–F) EM visualization of exosomes purified from isolated exosomes. Scale bars are 50nm.