Fig 1. Release of rhodamine B-labeled dextran from endosomes following light treatment.

Intracellular vesicles were preloaded with the photosensitizer. (a) The image of a COS7 cell before light treatment. It was taken at 20 min after the cell was incubated at 37°C with dextran (10,000 MW). The light treatment was performed immediately after the image acquisition. (b) The image of the same cell at 10 min after light treatment. The dextran was punctate within endosomes before light treatment (top panel). However, upon light treatment, dextran diffused out of endosomes, and spread in the cytosol (bottom panel).