In vitro phenotyping of recombinant hepatitis B virus containing the polymerase/reverse transcriptase gene from clinical isolates.

This chapter describes the procedures for the generation of recombinant hepatitis B virus (HBV) that contains the polymerase/reverse transcriptase (pol/RT) gene from clinical isolates. It also contains procedures for phenotypic testing of the recombinant HBV in HepG2 cells for susceptibility to nucleos(t)ide analogs. Amplification and cloning of the pol/RT gene as opposed to the full-length HBV genome from a clinical isolate allows for clinical samples with lower viral loads to be successfully analyzed. Furthermore, it enables a direct comparison of sequence changes in the pol/RT region between isolates.