 Exosomes are small vesicles 0.03-0.1 μm in size, which are shed from most cell types into the extracellular space via intracellular endocytosis. They are found abundantly in body fluids such as blood. They consist of lipid bilayer so that their structure is stable. They can be preserved for 2 weeks at 4C. They contain proteins, lipids and nucleic acids including coding or non-coding RNA. Resent studies have revealed that exosomes have an important role in cell-to-cell communication. 