Role of Specific Cellular Targets in the Hematoporphyrin‐sensitized Photoinactivation of Microbial Cells

The hematoporphyrin‐sensitized photoinactivation of Candida albicans is mainly carried out by porphyrin molecules which are present in the cell‐incubation medium. Photoexcitation of hematoporphyrin by visible light appears to cause limited biochemical and functional alterations of the cytoplasmic membrane; this allows the penetration of the dye into the cell, with a consequent important photoinactivation of the mitochondria. The latter process is of critical importance for the decrease in the survival of the irradiated cells.