Service description

Nanoparticle tracking analysis (NTA) service is performed in our laboratories by an experienced scientific team. 

The service results consist of a complete particle analysis descriptive report, as well as all the gathered support files including the raw data file and the video with the particle movement.

The results are returned by email within 5–10 business days after receipt of the samples.

In order to request the service, please select the service set up fee (catalogue code ZV-1) and the number of samples being sent for analysis (catalogue code ZV-12). The service set up is applicable for each individual shipment of a maximum of 8 samples. As an example, it is possible to receive a single shipment with 10 samples and in this case, the quantity 2 for the service set up should be selected.

Service requirements

The samples should consist of purified exosomes from cell culture media or any other biological fluid.

We recommend purifying intact exosomes via Exo-spin™ exosome isolation kit, resuspended in PBS. Ideally, exosome samples should not be purified using only precipitation reagents, as these can interfere with the NTA reading.

We require a minimum volume of 100 µl concentrated sample per measurement, irrespective of origin. All exosome samples should be sent on dry ice.

We can receive exosomes described as Biosafety Level (BSL) 1 or 2. For BSL2 samples, we require evidence of the following:

• Confirmation via PCR or equivalent test that the sample material is free of human pathogens (HBV, HCV, HIV-1, HIV-2, HTLV I/II, CMV, EBV, HSV-1, HSV-2) from a CLIA-certified lab.
• Confirmation via PCR or equivalent that the sample is free of mycoplasma. 

Concentration and particle counting

Prior to applying in the instrument counter, the exosome sample is diluted to 1500 µl to ensure adequate volume required for effective NTA performance. A minimum concentration of 1x10⁶ exosomes/ml is needed for the measurement, while the maximum concentration detected is 1x10¹⁰  exosomes/ml. For higher exosome concentrations, dilution is required, and our scientists will do all the calculations for you.

ZetaView® instrument

Cell Guidance Systems service uses ZetaView®, a second-generation instrument from Particle Metrix GmbH, which performs rapid in vitro measurement of physical parameters, including size, surface charge, and concentration of particles.

The ZetaView® instrument has been designed to do an automated scanning NTA. For a more representative analysis, the software measures 11 distinct positions in each sample which provides further information than single-point assessments, thus contributing to repeatable and reproducible results. Furthermore, automated parameters for auto-alignment and autofocus ensure that the video quality is kept constant while the particle movement is recorded.

This technology is well suited for use in exosome characterization, as it allows for easy and quick measurements, and is compatible with low concentrated and polydisperse samples.

ZetaView® instrument used for the NTA exosome profiling service 

NTA technology

NTA is a technique used for the simultaneous measurement and analysis of the size and concentration of single nanoparticles with high precision, accuracy, and reproducibility.

A laser is directed at the sample solution which generates light scattering by the particles in the sample. The NTA software captures the Brownian motion of each individual particle in a recorded frame-by-frame video. Large and small particles have different diffusion movements in solution which allows for the measurement of the hydrodynamic diameter of each particle using the Stokes-Einstein equation.

If you're starting out in exosome research

We designed the ideal starter pack to guide your exosome research. The starter pack includes the exosome purification kit of your choice, exosome validated antibodies, and NTA profiling analysis. The complete details can be found in the product page here.