Single Virus Tracing: Visualization of the Infection Pathway of a Virus into a Living Cell

Approach, contact, retreat; approach, contact, penetrate. With a number of fleeting subsecond contacts, the single virus moves across the cellular membrane (paths 1, 2 in the graphic) before it is suddenly engulfed (path 3). Although only a few viruses are successful, once inside they enter the nucleus in a matter of minutes (path 4), much faster than previously thought. Single virus tracing, the application of real-time single-molecule techniques to this biomedical problem, enables us to view the live scenes of viral infection with high spatial and temporal resolution and under ideal physiological conditions in a living cell. In this way, the “movie script” of a viral infection is obtained.