The VHSV culture supernatant was mixed with 0.1% formalin (v/
v) or not handled. Formalin-treated and non-treated viral fluids
were stored at 4 C and sampled immediately, followed by periodic
sampling until 168 h after formalin treatment. Each sample was
diluted 10-fold and quantified by assessing TCID50 in EPC cells
seeded in 96-well microplates.