Photomicrograph of Influenze Plaque Forming in Cell Culture

Pretty sweet right? This was published earlier this year in Science Magazine. You are watching the cytopathic effect of a single infectious particle dropped in the middle of the screen. The particle infects a cell, replicates and then spreads to neighbor cells. Virus titration and plaque counting is probably the oldest technique in virology, first used circa 1917 by Felix d'Herelle. In the following video, the virus is engineered to make a green fluorescent protein (GFP). Watch the infection front traveling ahead of the initiation of protein production, including the GFP.