High efficiency quantification of fluorescent labeled EVs with F-NTA

Nanoparticle Tracking Analysis (NTA) is an efficient technique for quantification of size and concentration such as virus, liposomes and EVs. Traditionally, detection of fluorescent particles (F-NTA) has been shown to be challenging due to bleaching effects known from laser induced fluorescence techniques (LIF). We present new implementations to increase efficiency and reproduciability in F-NTA.
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Colocalization-NTA of multi-stained platelet derived MSC-EV preparations
After successfully showing C-NTA of double-stained MSC-EVs in our previous study (https://bit.ly/43GG0Yk) and confirming
the results with image flow cytometry, this note describes C-NTA of multi-stained MSC-EVs using a PMX-430 QUATT NTA
system with four lasers.

Specific detection of SARS-CoV-2 corona virus from cell culture supernatants by fluorescence-based Nanoparticle Tracking Analysis
In this new application note we describe a quick determination of the physical titer of coronaviruses by fluorescence-based Nanoparticle Tracking Analysis and specific spike antibody recognition.

NTA goes colocalization:
Detection and measurement of CD9 and CD41 on
double-stained human platelet derived MSC-EV
preparations
In this report, we describe the quantification of colocalization ratios on double-stained MSC-derived EVs using fluorochrome conjugated antibodies against the
cell surface antigens CD9 and CD41, which also serve as EV marker proteins.

High Throughput ZetaView® System vs High Cost of Other Methods
In addition to using Nano Particle Tracking Analysis (NTA) to measurement the size distribution and concentration of EV samples, both Microfluidic Resistive Pulse Sensing (MRPS) and the Single Particle Interference Reflectance Image Sensor (SP-IRIS) methods have been widely used as an alternative means of characterizing EVs. In this note, we relay two specific cases for using the ZetaView® NTA system to achieve relative “high-throughput” analysis of many EV samples, along estimations of throughput for MRPS & SPIRIS methods for an equivalent number of samples; further, we establish realistic estimates for the high cost of ownership for operating MRPS & SP-IRIS systems as a result of the cost of consumables as well as the substantially greater amount of time spent to run the same number of samples.

Avoiding Artifacts in EV samples:
Part 1 – the Use of Tween®
Along with generally accepted methods are some “tricks of the trade” such as the addition of Tween® or BSA; however, some of those additions are problematic.

Rapid determination of purity, integrity and titer
of viruses by Fluorescence Nanoparticle Tracking
Analysis (F-NTA) using the bacteriophage Phi6
Determination of the titer of viruses and bacteriophages is an indispensable key technology in virological research and for diagnostic purposes. Depending on the method used, the measurements are either qualitative or quantitative, very time-consuming, and do not provide information about integrity or aggregation behaviour of the virus particles. Nanoparticle Tracking Analysis with the Particle Metrix ZetaView® instrument allows the user to perform a rapid concentration determination of virus particles. Using the bacteriophage Phi6 as an example, we show how titer, purity and integrity of phage particles can be measured quickly and reliably using the fluorescence detection capability of the Particle Metrix ZetaView® instrument.