Extracellular Vesicles (EV) interest have grown exponentially in the recent years. Characterization of EVs with conventional techniques like Western blot and Nanoparticles Tracking Analysis (NTA) is limited in scope and relies heavily on the quality of the sample preparation. Nanoscale flow cytometry has been used as a new way to identify, count and evaluate the origin of EVs. The CytoFLEX is a novel semiconductor-based flow cytometer that utilizes diode lasers, enhanced optics, wavelength-division multiplexing, and avalanche photodiodes to maximize light capture and minimize optical and electronic noise. The resolution of nanobeads as low as 80 nm has been demonstrated previously using the Violet Side Scatter (VSSC) on the CytoFLEX.
A rapidly expanding area in EV research focuses on characterization of new biomarkers of disease. The CytoFLEX can be of great benefit as flow cytometry allows the direct analysis of antigen expression on biological nanoparticles without having to achieve several step of ultracentrifugation or filtration which could altered the content of cells supernatant or biological fluids.
The current work describes a simple technique to standardize Nanoscale experiment with the CytoFLEX. A mixture of commercial polystyrene bead range from 80nm to 300 nm were used to measure scatter resolution. Material like viruses and exosomes were used to demonstrate the biological relevance of the range of resolution of the CytoFLEX.