Measuring the concentration of extracellular vesicles is challenging because they are small (hence, diffuse to fast) and they are very dim.
A way to overcome these limitations is to embed the particles in a hydrogel after fluorescently labelling them. This is the approach followed on the EVQuant protocol.
To measure the concentration, a light sheet microscope is used. We started off by using an OpenSPIM design, which was partially adapted to the needs of Dispertech, for example using a linear stage instead of a 4D stage, since one of the assumptions is that the sample is isotropically distributed.
One of the main limitations of the approach is that particles must be fluorescently labelled, and there is no way of discriminating false-positives. A large effort must be placed
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