ORF6 expressed from a plasmid adopts a similar subcellular localization to virally expressed ORF6 and colocalizes partially with CD63 and Lamp1. (A) Vero E6 cells were either transiently transfected with pXJ3'-ORF6 or infected with SARS-CoV. At either 16 hours post-transfection or at 75% CPE, cells were fixed and processed for immunofluorescence using an antibody directed against the ORF6 protein. (B) Vero E6 cells, which have been transiently transfected with ORF6, were fixed and stained for antibodies directed against ORF6 and either Lamp1 or CD63. Similar results were obtained in three independent experiments, and a representative set of data is presented.