Particle Metrix

Multiple–Laser ZetaView® f-NTA Nanoparticle Tracking Analyzers for the clinical research on extracellular vesicles, virus nanoparticles and membrane encompassed nano-objects. Analysis of concentration, size, zeta potential, RNA/DNA presence and phenotype

Identification of Exosomes using the tetraspanins CD9, CD63, CD81 and Particle Metrix ZetaView® fluorescent Nanoparticle Tracking (f-NTA)

Biological nanoparticles, such as extracellular vesicles (EVs), exosomes, lipids, viruses or proteins can be found in almost all fluids of living tissue. The Particle Metrix ZetaView® NTA technology is capable to characterize them reliably in water or physiological buffers. You can simultaneously get information about particle size, particle concentration and surface charge with just one single measurement of a particle sample. Similarly, cluster analysis based on similar properties is possible.

Insights into Multi Fluorescence NTA based EV Characterization – ISEV ‘EV imaging in vivo’ Workshop

Improvement on fluorescent Nanoparticle Tracking Analysis (f-NTA)

Multi-Fluorescence NTA – Next Generation EV Characterization with Particle Metrix ZetaView

Explore the Nanocosmos with Particle Metrix´s ZetaView

You see what you measure:

Concentration and patterns are constantly measured

The size is derived from Brownian motion

Z-NTA surface charged

 

Phenotype analysis by F-NTA

Particle concentration

The concentration of the particles is determined by the number of particles detected by the camera in a calibrated sample volume that is illuminated by the laser of the ZetaView® instrument. It is always apparent and will be displayed as “live read-out” as soon as a particle sample is introduced into the instrument, even if a measurement has not yet started. The color coding of the concentration display in the ZetaView® instrument shows whether the particles in the sample are in the optimum measuring concentration. Thus, a concentration adjustment of the sample can take place before the measurement.

Calculation of the hydrodynamic particle radius from the Brownian motion

Subgroups of particles result from cluster analysis using the parameters exemplified above. They can be plotted against each other in a scatterplot.

An electrophoresis experiment showed that a considerable number of particles showed flicker behavior. This phenomenon was interpreted by the customer as incipient crystallization. In this figure one particle each from the two sub-populations is shown in the course of the video.

Due to Brownian motion, small particles in liquid move much faster than large particles. Each individual particle in the field of view of the camera is detected and tracked in its movement in a two-dimensional direction. The measured change in location within a certain time interval t gives a specific diffusion coefficient D for each individual particle. Using the Stokes-Einstein relation, the ZetaView® calculates therefrom the hydrodynamic particle radius r and thus the diameter of each particle. The results are summarized and presented in a particle size distribution.

Calculation of the hydrodynamic particle radius from the brownian motion

Measurement of the ionic (electrical) surface charge by electrophoresis “Zeta potential”

Biological nanoparticles, such as extracellular vesicles, can be conjugated to fluorescently labeled antibodies and then analyzed for size, concentration, and, if required, for zeta potential and other pattern parameters in ZetaView® fluorescence mode. The particles to be analyzed should be sufficiently well purified and the conjugated sample must be freed from macromolecular substances and remaining free fluorescence molecules as well as small protein particles and lipids. Both, membrane dyes and primary and secondary fluorescently labeled antibodies can be used. By using the TWIN-laser system even phenotyping experiments can be performed on extracellular vesicles with a double-stained sample. For an experiment like this, two different fluorescent dyes conjugated to different antibodies are used to bind specifically to tetraspanins at the membrane surface (e.g., CD63-Alexa405 & CD81-Alexa488).

Available laser wavelengths, longpass (LP) fluorescence filters, and dyes that are very good or less suitable for photostability for the NTA.

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