Detection of Hepatitis B Virus Particles Released from Cultured Cells by Particle Gel Assay

The culture fluid of HBV replicating cells contains a mixture of viral particles with different structural and genetic components, including enveloped infectious virions, genome-free virion, envelope-only subviral particles, and nonenveloped naked capsids. Based on their different physical and chemical properties, the enveloped and nonenveloped particles can be separated by the native agarose gel electrophoresis and transferred onto a positively charged microporous membrane, then the virus particle-associated protein components and nucleic acid content can be detected by antibody-based enzyme immunoassay (EIA) and hybridization, respectively. Such convenient experimental procedure is called HBV particle assay and described in detail in this chapter. The particle gel assay can be used to study viral and host regulations of HBV virus morphogenesis and egress, and for antiviral assessment of HBV inhibitors as well.