Real-Time Fluorescence Detection of Protein Transduction into Live Cells

We describe a protein probe with multiple fluorescence signals that can unambiguously detect protein translocation into live cells. When combined with fluorescence microscopy, this unique probe design allows for the first time the investigator to visualize and distinguish intact and degraded proteins with high spatial and temporal resolution. Thus, by using this approach, one can now compare the mechanisms and measure the efficiency of different delivery vectors, a prerequisite for the rational design of protein transduction systems with superior properties.