There is a great deal of interest in characterizing small particles such as bacteria, extracellular vesicles, and viruses by flow cytometry. The common availability, as well as the multiparameter and high throughput capabilities of flow cytometry, make this technology attractive for measuring small particles. However, many of the flow cytometers currently being used are not able to detect biological particles smaller than 600nm, in fact very few can detect biological particles 300nm or less.
This lack of sensitivity has led to a bias in the literature toward larger particles, which in the case of extracellular vesicles, represent the smallest percentage of particles. While currently there are no flow cytometers that can detect the entire size range of submicron biological particles, Cytek has developed an Enhanced Small Particle (ESP) detection option for the already popular Aurora and Northern Lights flow cytometers.