Extracellular vesicles are the core of Cellarcus’ work. Our labs are equipped with specialized instrumentation and dedicated personnel for EV research. Our expertise is here for your pivotal studies.
Measure EV Size and Concentration
We measure the concentration and size distribution of your EV sample using our patent-pending vFC™ method. We report the concentration of EVs detected (limit of detection ~75 nm), the population size distribution, and the population light scatter intensity distribution. Samples will be measured in duplicate or in a dilution series (if the approximate concentration of EVs is not known).
Quantify Vesicle Cargo
We measure specific cargo on the surface of your vesicles using 100s of vFC™ optimized vTag™ antibodies. We can detect few as ~30 molecules of antigen using vFC™. Our screening assays have even greater sensitivity and examine optimized panels of markers (hematology, tetraspanins, stem cell, or tumor) for characterizing EV diversity in cell culture supernatants or biofluids from human, mouse, rat, dog, pig, or primate.
Custom Analysis Services
We are a full service CRO focused on EVs. In addition to our standard service offerings we support a range of research and development projects and are commonly involved from experimental design to data acquisition and analysis. If you need unique cargo measurements for therapeutic preps, standard or assay development, contract research and development services, or other project support, contact Cellarcus.
Sample requirements and recommendations
vFC™ analysis generally requires 100 ul of sample at an EV concentration of 1×107 EVs/uL. This will allow NTA analysis and limited titration in duplicate for initial vFC™ analysis. Once conditions are optimized, smaller volumes will suffice.
Purified EVs: vFC™ analysis is compatible with any of the popular EV enrichment methods, including ultracentrifugation, density gradient ultracentrifugation, polymer precipitation, filter binding, or filtration. A minimum volume of 100 uL at an EV concentration of 1 x 107 vesicles/uL or greater. If the EV concentration is not known, a dilution series will define concentration, limit of detection, and dynamic range of the analysis.
Culture media: EVs can be detected directly in serum-free culture supernatants, though EV concentrations are often too low. In general, it is recommended to concentrate culture supernatants 50-100x using centrifugal ultrafiltration (eg Amicon 100K MWCO centrifugal filter) or one of the other enrichment methods.
Plasma: Spin citrated blood at 2500 x g for 10 minutes to remove cells and large debris. Aspirate the supernatant and transfer to a new tube and repeat the spin. Aliquot the cell-free supernatant and freeze at -80°C. Plasma EV concentrations are in the range of 108-109 vesicles/uL, so aliquots of 25 uL generally suffice.
Cerebrospinal fluid: Spin CSF at 2500 x g for 10 minutes for cell and debris removal. Next, transfer the supernatant to a new tube and repeat. Aliquot the cell-free supernatant and freeze at -80°C. CSF EV concentrations are in the range of 105-106 vesicles/uL, so aliquots of at least 100 uL are required.
Other biofluids: Recommendations under development.
Data Produced by VFC Analysis
Vesicle concentration: in units of vesicles/uL
Vesicle population size distribution: estimated using well-characterized synthetic vesicles as reference particles
Vesicle surface protein frequency: percent positive above threshold level of detection
Vesicle surface protein abundance: in units of mean equivalent soluble fluorochromes (MESF) or estimated antibodies bound per vesicle (ABV)
Let’s work together
Need to send us sample info? Fill out this form. Get to the data that will describe the role of extracellular vesicles in your research aims. Fast forward to your discoveries.