Japan Tobacco Inc. 1 article published in JoVE Immunology and Infection Development of a Hepatitis B Virus Reporter System to Monitor the Early Stages of the Replication Cycle Hironori Nishitsuji1, Hiromi Yamamoto1, Ritsuko Shiina1, Keisuke Harada2, Saneyuki Ujino1, Kunitada Shimotohno1 1Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, 2Central Pharmaceutical Research Institute, Japan Tobacco Inc. Here we describe a newly developed hepatitis B virus (HBV) reporter system to monitor the early stages of the HBV life cycle. This simplified in vitro system will aid in the screening of anti-HBV agents using a high-throughput strategy.