Beckman Coulter Cytoflex Nano for Sub-Micron Flow Cytometry - PROJECT SUMMARY/ABSTRACT The University of California at Davis (UCD) is a diverse educational institution recognized for excellence in medical, veterinary, agricultural and engineering education and research. The UCD Medical Center houses the UCD Comprehensive Cancer Center (UCDCCC), a patient treatment and research center that supports and coordinates the collaborative research efforts of over 100 cancer researchers. The UCD Flow Cytometry Shared Resource Laboratory (FCSR) provides cell sorting and analytic cytometry support campus-wide and is used heavily by UCDCCC members. In recent years, several UCDCCC investigators have begun to study the role of small, nanometer sized extracellular vesicles, such as exosomes, in cancer diagnosis, metastasis and treatment. Extracellular vesicles (EVs) are a variety of nanoscale membrane vesicles released by cells that are widely present in body fluids. The study of EVs is hampered by their small size (≤100nm), as well as their variable surface protein expression and internal composition. Flow cytometry is a preferred method to rapidly characterize, enumerate and purify EVs based on size and brightness. However, many clinically-relevant EVs are between 30-80nm and fall below the limit of detection of most standard flow cytometers. EV research also requires rigorous isolation and labeling techniques, and detecting EVs apart from instrument and reagent noise is challenging, especially for novice EV investigators. Certain cytometers, such as the FCSR’s 8-year-old Beckman Coulter “Cytoflex S”, have sufficiently sensitive optical detectors and other features that allow it to detect EVs 80nm. For the past four years, this Cytoflex S has supported the EV cytometry needs of UCDCCC investigators. However, the Cyoflex S was not specifically designed to support consistent, reliable EV measurements and suffers from periodic optical drift and other issues that are difficult to address. This situation has led to unacceptable unreliability of the Cytoflex S platform for EV work. Further, at its best, the Cytoflex S cannot detect EVs smaller than 80nm. Meanwhile, as the role of flow cytometry has gained more importance in the EV field, new cytometers, like the Cytoflex Nano, have been developed specifically to support EV research. The proposed Cytoflex Nano, described in this application, is engineered exclusively for EV research, is capable of detecting particles as small as 40nm, has rigorous cleaning and QC procedures that simplify cytometer setup and qualification for EV studies and will receive improved maintenance support from the supplier. The success of NIH-supported EV research at UC Davis depends on the availability of a sensitive, reliable, small particle cytometer that will simplify the user experience and enable biomedical breakthroughs. The Cytoflex Nano will be housed in, managed and maintained by the Flow Cytometry Shared Resource facility so that UCD investigators have access to sensitive, reliable nano-particle detection and EV flow cytometry expertise for years to come.
