qNano for the study of Exosomes & Microparticles
Microparticles and exosomes are microvesicles present in body fluids, derived from the plasma membrane of cells and platelets. They play important roles in normal processes (coagulation, inflammation, cellular homeostasis and survival, intercellular signaling, and transport of waste materials) as well as a number of disease states.
The size, concentration, and biochemical composition of these vesicles contain clinically relevant information – that is expected to lead to improved diagnosis and treatment of disease. However, because of the small size of most vesicles (30 nm – 1 µm), they are below the detection range of many currently used techniques.
qNano is a powerful research tool for the characterisation of biological particles under physiological conditions, opening up previously unavailable capability in microvesicle analysis.
Introduction
The size, concentration, and biochemical composition of microvesicles and exosomes are clinically relevant information – that could lead to improved diagnosis and treatment of disease. However, because of the small size of most vesicles (30 nm – 1 µm), they are below the detection range of many currently used techniques.
qNano is new non-optical solution, which uses size tunable nanopores to detect vesicles directly in suspension and provides increased sensitivity compared to flow cytometry, and improved accuracy over light-based technologies. qNano enables particle-by-particle collection & assessment, providing accurate determination of size, concentration and relative surface charge of vesicle samples.
Click Here to Discuss Your Needs
Charge Assessment for Disease Marker Detection
Example 1: Exosomes in Human Serum
Exosome vesicles present in human serum were characterised using the qNano platform. High resolution, particle-by-particle measurement allows differences between individual particles to be accurately resolved.
Figure 1. Particle size distribution for Exosome samples. The addition of an exosome preparation (red) is detected as an increase in regions of a size distribution curve, where a high exosome concentration is present, in comparison to serum alone (blue).
Figure 2. Particle Diameter versus Translocation Duration for Exosome samples. Translocation duration refers to the time taken by individual particles to cross the nanopore, and provides an indication of the relative surface charge of particles.
Charge Assessment for Disease Marker Detection
The detection of antibody-specific binding to disease markers, with the qNano systen, can be used to differentiate 'healthy' versus 'disease' cell populations such as cancer cells.
In Figure 3, Exosomes alone (red) and with the addition of a non-specific antibody (blue) are indicated. Green indicates the addition of a specific antibody for the disease of interest (DOI). Antigen-specific binding to the exosome surface causes a change in surface charge, and decrease in electrophoretic mobility, shown as increased translocation duration for this sample (green). This provides positive confirmation and detection of the antigen-bearing exosome sample.
Figure 3. Translocation Duration distribution for Exosome Preparations. Red shows Exosomes alone, Blue shows addition of non-specific antibody, green shows addition of specific antibody for a marker of the disease of interest.
Example 2: Exosomes in Human Urine
The size distribution and a plot of translocation duration against particle diameter for exosomes in human urine are illustrated in the following figures.
Figure 4. Size Distribution and Concentration of Urinary Exosomes.
Figure 5. Translocation Duration versus Particle Diameter for Exosomes in Urine.
Conclusions
qNano is a useful tool the the characterization of exosomes preparations.
Key features include:
- Accurate vesicle-by-vesicle measurement.
- Charge assessment for confirmation of binding events.
- Antibody-specific binding to disease markers can be used to differentiate 'healthy' versus 'disease' states
- Measurement at physiologically relevant conditions.
For more information please contact us at info@izon.com
