Hypericin uptake and intracellular localization.

<p>Cells were exposed to 3 µM hypericin for 4 h without light activation. (A) Hypericin uptake assay. Data is shown as mean±SEM relative fluorescent units per microgram of protein (RFU/µg of protein, n = 3, *p<0.05). (B) Live confocal fluorescent microscopy images of melanoma cells indicate the intracellular localization of hypericin (red) in relation to the endoplasmic reticulum (ER-YFP), mitochondria (OTC-GFP), lysosomes (Lysotracker yellow) and mature melanosomes (MyosinVa-GFP). Nuclei were counterstained with Hoechst (blue). Profiles taken at different locations through the cell indicate co-localization of the fluorophores. A representative result is shown (n = 3, scale bars: 10/20 µm).