This colorized negative stained transmission electron micrograph (TEM) showed recreated 1918 influenza virions that were collected from the supernatant of a 1918-infected Madin-Darby Canine Kidney (MDCK) cell culture 18 hours after infection. In order to sequester these virions, the MDCK cells were spun down (centrifugation), and the 1918 virus present in the fluid was immediately fixed for negative staining.