University of Agriculture in Krakow 1 article published in JoVE Immunology and Infection Isolation of Low Endotoxin Content Extracellular Vesicles Derived from Cancer Cell Lines Aneta Babula*1,2, Izabela Siemińska*1,3, Monika Baj-Krzyworzeka1 1Department of Clinical Immunology, Jagiellonian University Medical College, 2Doctoral School of Medical and Health Sciences, Jagiellonian University, 3Institute of Veterinary Sciences, University Center of Veterinary Medicine JU-AU, University of Agriculture in Kraków The proposed protocol includes guidelines on how to avoid contamination with endotoxin during the isolation of extracellular vesicles from cell culture supernatants, and how to properly evaluate them.