Extracellular Vesicles Nanoparticle Analysis

Table of Contents

Extracellular Vesicles and Exosomes
     Fraction Analysis
     Robustness and Repeatability
Distinguishing EVs of Various Origin

Extracellular Vesicles and Exosomes

Extracellular vesicles (EVs), including exosomes, hold significant promise as biomarkers, as innovative therapeutics and commonly as a source for new understanding of biological processes. Their physical characterization however has until now presented two major challenges: Both the concentration and size of EVs range multiple orders of magnitude, and they scatter light weakly, making accurate characterization by optical methods difficult. Spectradyne's nCS1 instrument, based on microfluidic resistive pulse sensing (MRPS), provides practical solutions to both challenges in a quick and robust analysis system.

Fraction Analysis

Urinary exosomes were divided using sucrose gradient ultracentrifugation, and three fractions were examined with the nCS1. Results are illustrated in the figure below. The nCS1 measurements exposed slight differences in the size distribution of EVs in the fractions, and decisively, reveal that each fraction comprises EVs spanning over 400 nm in diameter, and four orders of magnitude in concentration. Characterization of these samples in such fine detail would not be possible using optical methods because of the low refractive index contrast of the samples.

Extracellular Vesicles Nanoparticle Analysis

Robustness and Repeatability

The reliability of EV measurements acquired with the nCS1 was shown using cell culture media. Triplicate measurements were performed of the EV size distribution in cell culture supernatant. Notably, no sample preparation of any kind was necessary prior to measurement. The results reveal very high repeatability: Difference in the measured concentration on the size range of 250-2000 nm was less than 3% (refer the table below).

Run Measured Concentration
1 5.44 x 107 particles/mL
2 5.25 x 107 particles/mL
3 5.09 x 107 particles/mL

 

Distinguishing EVs of Various Origin

Distinguishing EVs of Various Origin

The nCS1’s high resolution enables quantitative differentiation of EVs from various sources. The figure below illustrates this application for five different EV samples, with the concentration values displayed over the range from 140-400 nm in diameter.

The Spectradyne nCS1 is a useful tool for high-fidelity EV characterization: Usual measurement time is approximately 3 minute/sample, and the system offers accuracy and resolution that are superior to other metrologies. Disposable microfluidic cartridges require just 3 µL of sample per measurement, eliminate cleaning between samples, and deliver engineered features to minimize or eliminate blockages of the sensing constriction.

The table below shows the integrated concentration levels for each EV sample plotted at right.

Sample Measured Concentration
#4 Erythrocyte (9.7 ± 0.1) x 109 particles/mL
#5 Platelet (2.44 ± 0.02) x 1010 particles/mL
#6 Plasma (1.09 ± 0.01) x 1010 particles/mL
#7 LNCAP (1.98 ± 0.05) x 109 particles/mL
#8 PC3 (1.58 ± 0.05) x 109 particles/mL

 

Spectradyne

This information has been sourced, reviewed and adapted from materials provided by Spectradyne.

For more information on this source, please visit Spectradyne.

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