Exosomes / Extracellular Vesicles (EVs) are an emerging class of biologics that play a crucial role in intercellular communication and hold tremendous promise. A key challenge in the translation of exosomes is the implementation of robust analytical methods for characterization. The size, heterogeneity, and complex composition of exosomes creates challenges for the use of conventional analytical tools and strategies, especially for critical quality attributes such as purity and potency.

RoosterBio has developed an extensive panel of analytical methods to support process development and manufacturing of exosomes, which we offer to our customers as either a stand-alone service or as an integrated component of a broader process development program. Our standard exosome analytics are bundled into a Base Package and Plus Package, along with additional supplemental assays to meet a broad range of customer needs, regardless of their cell type or production process.

We Offer Two Exosome / Extracellular Vesicle Analytics Packages & Supplemental Assays Specially Designed for Starting & Advanced Programs Alike

Assay	Assay Result	EV / Exosome Base Package	EV / Exosome Plus Package	Supplemental Assay
Nanoparticle Tracking Analysis (NTA)	Particle Number, Particle Size	✓	✓
EV / Exosome Purity	% EV by Particle Concentration	✓	✓
Protein Quantitation	Total Protein	✓	✓
Surface Marker Expression	Marker Expression	✓	✓
Cytosolic Marker Expression	Alix Expression		✓
miRNA Quantitation	miRNA Content		✓
miRNA Identity Analysis	miRNA Identity		✓
Lipid Content	Total Lipid Content		✓
Albumin Analysis	Process Related Impurity		✓
CD63 Quantitation	Quantified Marker Expression			✓
Scratch Assay	Wound Healing			✓

Advanced Equipment for Advanced Analytics

ProteinSimple – Simple Western Jess

NanoFCM Flow NanoAnalyzer

ThermoFisher Attune NxT Flow Cytometer

ThermoFisher QuantStudio 5 Real-Time PCR System

Nanoparticle Tracking Analysis (NTA)

Nanoparticle Tracking Analysis is one of the most widely used methods for characterizing extracellular vesicle identity. This assay utilizes light scattering to quantify the size distribution and concentration of particles in a sample which are two key identity components of extracellular vesicle characterization. Results are provided as a concentration in particles per mL and a size distribution graph of extracellular vesicle diameters. This standardized assay is conducted using a NanoSight NS300 but has available options of ZetaView and nanoFCM Flow NanoAnalyzer.

Extracellular Vesicle / Exosome Purity

This extracellular vesicle assay uses the ZetaView’s fluorescent capabilities to measure the purity of your samples as a percent of particle population with membrane-bound lipids. As a result, these results will inform you what percentage of your particle concentration is made up of extracellular vesicles. Additional assays can utilize either the ZetaView or nanoFCM Flow NanoAnalyzer to assess tetraspanin make-up of the particle population and custom target readouts for your target of interest upon request.

Protein Quantitation

This protein quantitation assay is a widely used identity and content tool to measure total protein content of an extracellular vesicle sample. Quantitation of protein content is a useful metric for process optimization as well as characterization of a purified sample. Results are provided as total protein per mL and a bicinchoninic acid assay (BCA), microBCA, or Bradford assay will be used depending on customer preference and sample submission.

Surface Marker Expression

CD9, CD63, and CD81 are tetraspanin proteins widely expressed in different cell types and considered identity markers of extracellular vesicles. This western blot assay provides a sensitive, semi-quantitative readout via image and densiometric conversion for all three tetraspanins in sample preparations. Additional assays utilizing the nanoFCM Flow NanoAnalyzer or Simple Western Jess to asses these tetraspanins or your surface markers of interest are available upon request.

Cytosolic Marker Expression

This identity assay is a quantitative Alix ELISA that measures a MISEV-recognized cytosolic marker in extracellular vesicle preparations. Results are provided as Alix protein per mL.

miRNA Quantitation

Bioanalyzer quantitation of miRNA content, as well as miRNA size distribution, provides a critical content readout for understanding your extracellular vesicles. Results are provided as miRNA concentration (miRNA per µL), gel view of miRNA migration, and electropherogram of size and signal intensity. This assay can also quantify total RNA should it be preferred.

miRNA Identity Analysis

Quantitatively identify specific miRNAs present in your extracellular vesicle samples. This real-time qPCR analysis provides readouts across several functional categories as well as a minimum of two reference readouts. Additional readouts can be customized to your target of interest upon request.

Lipid Content

This plate reader-based fluorescence identity and content assay provides a quantitative measurement of total membrane-bound lipid content per mL.

Albumin Analysis

This quantitative ELISA measures human albumin which is a common media component but impurity when found in extracellular vesicle preparations. Step-wise removal of albumin can be an informative analytical readout as well as a purity indicator for “final product” extracellular vesicle samples. The results of this purity assay are reported as albumin protein per mL.

CD63 Quantitation

Used for process development, this identity assay is a quantitative ELISA, which measures a MISEV-recognized surface marker in extracellular vesicle preparations. Results are provided as CD63 protein per mL.