Although not all cells are morphologically intact at 72 hours postinfection, with GIV or BTV-8, at this stage NS4 was present in the cell membrane ( figure 12A, 12B) . This is consistent with bioinformatic analysis showing similarities between NS4 and membrane-associated proteins. Another set of cells, which were collected at 36 hours PI contained cells at different stages of infection. Those at an advanced stage of infection had depolymerised and depleted tubulin (figure 13A). No immuno-fluorescence signal was detected when non-infected cells were labelled using anti-NS4 antibodies (figure 13B, indicating that the anti-NS4 antiserum does not cross react with cellular proteins.