Approximately 300 million people are chronically infected with the hepatitis B virus (HBV), which can cause liver cirrhosis or cancer. Consequently, there is an urgent need for the development of HBV curative therapies. Due to the unique replication strategy of HBV, however, quantification of viral DNA in infected liver cells, which is essential in preclinical and clinical studies, is technically difficult and not standardised. An international research consortium led by DZIF scientists has now developed recommendations for the optimisation, control and validation of quantitative viral DNA measurements, which could be crucial for preclinical and clinical evaluation of therapeutic strategies.