The Zetaview small particle analyzer employs Nanoparticle Tracking Analysis (NTA) which relates the rate of Brownian motion of the particles in liquid suspension to particle size. The rate of movement is related to the viscosity and temperature of the liquid; it is not influenced by particle density or refractive index. NTA allows the determination of a size distribution profile of small particles with a diameter of approximately 10-1000 nanometers (nm) in liquid suspension. Additionally, the Zeta View is also capable of measuring the so-called zeta-potential of the particles which is a measure of the electric charge on the nanoparticle surface.

Our facility has two ZetaView analyzers which share a single flow cell module which is interchangeable between the two analyzers. One analyzer is equipped with a 488nm laser while the other is equipped with 405nm laser. For particle size, concentration and zeta potential measurements, the 2 analyzers can be used interchangeably. When detection of fluorescent particles is desired, the analyzer of choice needs to match the excitation spectrum of the intended fluorochrome to be detected.

The primary application of the NTA analysis at Roswell Park is in the field of extracellular vesicles (EV) research where NTA is the accepted method for determining size distribution and concentration of EVs. Exosomes are cell-derived vesicles with a diameter between 30 and 100 nm. Evidence is accumulating that exosomes have specialized functions and play a key role in intercellular communication and can potentially be used for prognosis, for therapy, and as biomarkers for health and disease. Amongst the many detailed studies of exosomes that can include studying their phenotype and cargo, measurement of their size and concentration are additional key parameters in the context of their biological function.

The ZetaView instruments are QC’d daily and are available 24/7 to trained users by reserving time on the FOM calendar. For training, please contact Hans Minderman (716-845-1162).