To verify whether the NiV proteins were incorporated into the VLPs as designed, purified particles were analyzed by western blotting using NiV-specific mouse antibody, and HRP-conjugated anti-mouse secondary antibody as described under Methods. The right hand panel in the Figure 3 shows VLP-incorporated proteins in two different preparations of NiV VLPs. The protein bands are consistent in size to NiV proteins G, F 0 , F 1 and M proteins [17, 48] . The relative amounts of the VLP-incorporated G and M proteins appeared to be similar to that reported in NiV virions also [17] . This was in spite of the fact that the viral proteins in that study were revealed using rabbit sera raised against bacterially expressed Hendra virus proteins. However, the ratio of the VLPincorporated F 1 to F 0 was different from that in the virions. This difference is more likely to be a reflection of timing and protein turnover rather than the reagents used to reveal them since in a previous study, pulse chase experiments have shown that similarly to the VLP-incorporated F 1 to F 0 , intracellular cleavage of the precursor NiV fusion protein by cathepsin L results in near equal mix of mature fusogenic, and the precursor forms [65] . Absence of the NiV-specific bands in two different 293T cell lysate preparations processed similarly (and shown in the left hand panel in Figure 3 ) confirms specificity of the VLP-incorporated proteins.