Interest in exosome research has increased dramatically in recent years due to their unique functions as intercellular messengers, abilities to alter recipient cell bioactivities, as well as in disease diagnostics. Despite significant efforts made in this relatively new field of research, progress has been held back by challenges such as inefficient separation methods, difficulties in characterization, and lack of specific biomarkers. Current applied methods for exosome purification are ultracentrifugation, precipitation with PEG, immunocapture with antibodies against CD9, CD63, CD81, TSG, Rab5 and others, microfluidic isolation or filtration. All these methods do not isolate all exosomes mainly subpopulations or even destroy the microvesicles during purification. For example, exosome quantity and integrity are dependent not only on the blood drawing method but also on storage conditions. As depicted in the Figure below exosomes captured with Rab5 and ExoMag demonstrates that EDTA plasma results in the highest yield. Any storage condition gives lower yields in comparison to fresh samples.
