A Fluorescent In Situ Hybridization (FISH) Assay for Detection of HBV RNA, DNA, and cccDNA in Cell Culture.

Hepatitis B virus (HBV) is undoubtedly a master in exploiting host resources while evading host defense for its multiplication within a constrained genetic coding capacity. To further unravel these cunning strategies, a clear picture of virus-host interaction with key subcellular and molecular contexts is needed. Here, we describe a FISH protocol modified from the ViewRNA assay that allows direct visualization of HBV RNA, DNA, and cccDNA in cell culture models (e.g., HepAD38, HepG2-NTCP). It can be coupled with immunofluorescence staining of viral or host proteins or other fluorescent tagging systems which could illuminate numerous aspects of virus-host interactions.