To assess the role of NTCP in HBV internalisation we inoculated HepG2 and HepG2-NTCP cells with virus (multiplicity of infection, MOI, of 200 genome equivalents per cell) for 1 h at 4°C and transferred the cultures to 37°C for 1 h, 3 h or 6 h prior to digesting with trypsin to remove non-internalised particles and quantifying intracellular HBV DNA. Here, SLC10A1 is linked to infection.