For immunofluorescence antibody test, Vero cell monolayers were prepared in 8-well chamber slides by seeding at a concentration of 30,000 cells/well in 300 ml of cell media and incubating over night at 37uC. The cell monolayers were infected with an MOI of 0.01 of CedPV, HeV or NiV and fixed with 100% ice-cold methanol at 24 h post-infection. The chamber slides were blocked with 100 ml/well of 1%BSA in PBS for 30 min at 37uC before adding 50 ml/well of rabbit sera against CedPV N or NiV N diluted 1:1000. After incubation at 37uC for 30 min, the slides were washed three times in PBS-T and incubated with 50 ml/well of anti-rabbit 488 Alexafluore conjugate (Invitrogen) diluted 1:1000 at 37uC for 30 min. The slides were then washed three times in PBS-T and mounted in 50% glycerol/PBS for observation under a fluorescence microscope.