Measuring Exosome Stability with Nanoparticle Tracking Analysis

The study of extracellular vesicles is an area that has become the subject of intense study and research in recent years. These vesicles are apparently ubiquitous in a broad range of prokaryotic and eukaryotic organisms and it is believed they have a wide role to play in many physiological and pathological processes. They are typically described either as exosomes which are produced from the cell endosome or microvesicles, produced by cell membrane budding. Their cellular origin, structure, functions and characterization are still the subject of much debate. Also debated by the research community are the size of such vesicles though exosomes are agreed to be smaller in size (typically 100 nm in diameter or smaller) whilst micro vesicles are larger (typically described as being up to 1 μm in diameter).

Whilst research continues to provide insight into the role and potential clinical link of these vesicles, it is important to understand the stability of any sample under study to ensure that any differences are truly attributable to the test conditions and not to any inherent instability of the sample itself.

Here we describe the use of Nanoparticle Tracking Analysis (NTA) for size and concentration measurements of exosomes when stored at 4°C and at room temperature for up to 5 days.