Exosomes have been studied widely as information-rich sources of potential biomarkers that can reveal cellular physiology. Quantification is essential to understanding basic biological relationships between exosomes and their parent cells and the underlying interpretation of exosome signals. We use the following methods to quantify exosome particles:
- Electron microscopy (EM): To distinguish between exosomes and other vesicles.
- Nanoparticle Tracking Analysis (NTA): It follows single particle movement into a solution and calculates their hydrodynamic diameter based on Brownian motion equations. It provides size, zeta potential and exosome distribution per volume of sample.
- Tunable Resistive Pulse Sensing (TRPS): It provides both concentration and size information.
- Vesicle Flow Cytometry: To provide an individual count of vesicles in solution characterized by the presence of specific markers.
- Surface Plasmon Resonance: To determine the vesicle concentration in a solution by measuring the rate of arrival of the vesicles to a sensor surface under mass transport limited conditions.