Abstract 1991: Exploring the potential of exosomes for cancer diagnosis and management: Comparative analysis of isolation methods for optimum yield purity and downstream applications

Abstract

Abstract Exosomes have received significant attention due to their involvement in several diseases, including cancer, and are being explored as a tool for disease diagnosis and management. As a result, several kits based on different principles are now available in the market for exosome isolation. In this study, we have compared the relative efficacy of four commercial kits from Invitrogen, 101Bio, Wako and iZON along with conventional ultracentrifugation-based method for exosome yield, purity and quality for downstream applications. Cancer cell culture supernatant was used as an abundant and uniform source of exosomes for all methods and exosome quantity, size distribution, zeta potential, marker expression, RNA (qRT-PCR) and protein (mass spectrometry) quality was determined. The Invitrogen method showed the highest yield but the preparation showed broader size distribution likely due to co-precipitation of microvesicles and had the least magnitude of zeta potential (dispersion stability). Exosome preparations from other methods showed accepted size range (<150 nm) with a variable zeta potential (-12mV to -29mV) with good purity. The gel filtration method; however, showed a broader size distribution in the lower size range, which could be due contamination of aggregates of proteins and vitamins molecules. Quality of RNA isolated from all preparations was comparable; however, proteins isolated from Invitrogen method-based exosomal preparation showed contamination of polyethylene glycol (PEG) in mass spectrometry analyses. Similarly, other chemical impurities coming from the precipitant in Invitrogen kit could also be the reason for toxicity of resultant exosomal preparation in biological growth measurement assay. Together, these findings from comparative analyses should serve as a guide for choice and further optimization of exosome isolation methods for their desired downstream applications in cancer biology, therapy and/or biomarker discovery. Citation Format: Girijesh K. Patel, Mohammad Aslam Khan, Haseeb Zubair, Sanjeev Kumar Srivastava, Moh’d Khushman, Seema Singh, Ajay Pratap Singh. Exploring the potential of exosomes for cancer diagnosis and management: Comparative analysis of isolation methods for optimum yield purity and downstream applications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1991.