American University of Beirut 1 article published in JoVE Immunology and Infection Isolation and Quantification of Epstein-Barr Virus from the P3HR1 Cell Line Elio R. Bitar1, Marcel S. Shams Eddin1, Elias A. Rahal1,2 1Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, 2Center for Infectious Diseases Research (CIDR), Faculty of Medicine, American University of Beirut This protocol permits the isolation of Epstein-Barr virus particles from the human P3HR1 cell line upon inducing the viral lytic cycle with phorbol 12-myristate 13-acetate. DNA is subsequently extracted from the viral preparation and subjected to real-time PCR to quantify the viral particle concentration.