Relationship between hemagglutinin stability and influenza virus persistence after exposure to low pH or supraphysiological heating
Fig 5
HA activation pH values measured by syncytia formation assay.
Viruses identified by the numbers on the left side of each row (cf. Table 1) were inoculated into Vero cells at an MOI of 3 PFU/cell. The pH values for PBS overlaid onto the cells are reported on the top left of each microscopic image. HA activation pH was defined as the highest pH at which syncytia formation occurred (third column).