A typical acquisition time for a FLIM image is 5-10 min, hence fast dynamics of the PDT process cannot be resolved. By contrast, morphogenic changes can be visualized much faster with widefield fluorescence images. Fig. shows selected frames of a video recorded at 0. protuberances and the overall PL intensity increases drastically throughout the whole cell body and distinctively in the nucleolus. This results from an increasing PI intercalation into RNA and DNA fragments in the cytoplasm due to cell membrane damage. At later PDT stages, an explosive rupture of the cell membrane (Fig. ) occurs after 5 min of irradiation. The final stage of PDT is illustrated in Fig. , where the rounded cell exhibits a high total fluorescence intensity signal, mostly caused by PI, suggesting cell death.