Imaging of vaccinia virus entry into HeLa cells.

The recently developed technique of live cell imaging has found numerous applications, including the detection of virus movements in living cells. To monitor virus motility, viruses or cellular proteins are fused with fluorescence markers and then detected by time-lapse fluorescence microscopy. These techniques allow kinetic analyses of individual virus particles in motion during the virus entry process as well as monitoring of dynamic interactions between viruses and cellular structures in real time. The methods presented here describe how to construct a fluorescent recombinant vaccinia virus expressing the core protein A4L fused to mCherry, and how to detect the virus movement on actin-EYFP-expressed HeLa cells.