Characterization of exosome subpopulations from RBL-2H3 cells using fluorescent lipids

When the bulk of exosomes was labeled after their purification (“in vitro labeling”) with either of the above-mentioned lipid probes, the Bodipy-Cer was the only one to incorporate noticeably in all the subpopulations, indicating that the previous results obtained during “in vivo labeling” monitored real intracellular lipid trafficking between organelles and exosomes. Bodipy-Cer was further used as a tool to measure the respective amounts of each subpopulations. CD63, MHC II, and CD81-containing exosomes accounted for 47%, 32%, and 21%, respectively, of total exosomes.