It is said that exosomes are difficult to be analyzed by flow cytometry, due to their very small size (30 - 100 nm). Fujifilm Wako developed a flow cytometry kit for exosome analysis by combining Tim4 protein, which specifically binds to phosphatidylserine on the surfaces of extracellular vesicles, including exosomes, and magnetic beads. This kit enables easy and sensitive flow cytometry analysis of exosomes without purification.