Ludwig-Maximilians-University, Department of Chemistry and Center for NanoScience, Butenandtstr. 11, D-81377 Munich, Germany
A single fluorescent dye-molecule was attached to the protein capsid of an Adeno-associated virus in order to follow its migration into a living HeLa cell by single molecule techniques. Only one dye-molecule was used not to influence the specific virus-cell compartment interactions and to keep true physiological conditions. The infection entry pathway of such an individual labeled virus could be monitored in real time with high spatial (40 nm) and time (10 ms) resolution. A movie is obtained following the infection pathway from the first touch of the virus with the cell surface to the final deposition of the virus DNA in the nucleus of the cell. Thus all stages of the infection pathway can be monitored in great detail revealing the 'movie script' of a virus infection. This is of relevance to an understanding of the pathogenic mechanisms of a virus infection. In addition single virus tracing experiments can be applied to both improvement of limitations of virus-mediated gene delivery in living cells (e.g. viruses as gene shuttles in gene therapy) and development of antiviral drugs.