His-tag based in situ labelling of progeny viruses for real-time single virus tracking in living cells.

Tracking virus infection events in live cells is useful for understanding the mechanism of virus infection, and fluorescent labelling is a critical step. Herein a noninvasive strategy for labelling viruses with His-tags was developed by in situ modifying the cell surface proteins with polypeptides containing His-tags during progeny virus assembly. The His-tagged viruses were further conjugated with Ni-nitrilotriacetate complex modified quantum dots, and retained their infectivity for real-time single virus tracking in living cells.