The small size and physicochemical heterogeneity of exosomes make their physical characterization and quantification an extremely challenging task. Creative Biolabs has successfully launched an innovative exosome quantification platform with multiple high-end technologies to detect and quantify exosomes in complex biological samples.
Exosomes are small vesicular structures that represent a novel source of biomarkers for the state of the cells from which they are derived. Typically, quantification is very important to understand basic biological relationships between exosomes and their parent cells, as well as the underlying interpretation of exosome signals. As interest in exosomes expended, the number of methods for quantifying exosomes has increased. In previous studies, three groups have illustrated the importance of quantifying exosomes, examining the stoichiometry of miRNAs per exosome. For example, Akers et al. isolated extracellular vesicles, primarily exosomes, from cerebrospinal fluid (CSF) samples and then measured the number of exosomes via nanosight nanoparticle tracking analysis and the total content of specific miRNAs by qRT-PCR. Creative Biolabs offers a variety of techniques for exosome quantification to satisfy our customer’s needs.
Fig.1 Schematic of protein and RNA transfer by EVs. (Raposo, 2013)
Quantification is essential to understand basic biological relationships between exosomes and their parent cells and hence the underlying interpretation of exosome signals. Creative Biolabs offers robust technologies to fulfill the demands.
Nanoparticle Tracking Analysis provides a combined analysis of Brownian motion via light scattering to count and size nanoparticles in a liquid suspension. Particles in suspension passed through a flow chamber and are illuminated using a laser source. The light scatter produced from this is recorded using a video camera.
Tunable resistive pulse sensing (TRPS) detects the passage of individual particles through a pore in a membrane, and operates similarly to a Coulter counter. TRPS detection provides both concentration and size information.
Exosomes are captured at the bottom of a microwell and the amount of biomarker detected with antibodies generating a fluorescent or colorimetric signal. With the aim to provide a quantitative estimate of the amount of exosomal vesicle (EV) material carrying a specific marker from such assays, attempts have been made to relate specific protein content to total particle content using calibration curves established with characterized exosomal samples.
Fig.2 Chip design and principle for exosome capture and detection. (Fang, 2017)
Flow cytometry detects particles suspended in a fluid by their interaction with a laser beam as they flow through a detection cell. Flow cytometry can take advantage of fluorescent-based immunostaining to provide an individual count of vesicles in solution characterized by the presence of specific markers.
Surface-based sensors are used to determine the vesicle concentration in solution by measuring the rate of arrival of the vesicles to a sensor surface under mass transport limited conditions. Under such conditions, the initial binding rate is directly proportional to the concentration and the diffusion coefficient of the vesicles.
With the help of our well-established technologies and experienced scientists, Creative Biolabs is capable of detecting and quantifying exosome in complex biological samples. We provide very flexible options for each specific case. We fully understand the advantages and limitation of each technology, and will help you choose the most appropriate technology to meet your specific needs. We are happy to make it accessible to all kinds of research and industrial customers. Please don’t hesitate to contact us for more information.