Fig. 4.

Determination of cell line susceptibility to hCoV infection by in-cell ELISA. Vero E6, Calu-3, Caco-2 or Huh-7 cells were seeded and on the following day inoculated with a 2-fold serial dilution of a) hCoV-229E, b) -NL63, or c) -OC43 at indicated MOIs. According to the established in-cell ELISA, cells were fixed and stained at 2–6 days post infection (d2-d6). Input control measured 2 h post infection was subtracted from the corresponding values on later time points. Data are presented as mean ± SD of one experiment conducted in 2–6 replicates.