The invention relates to a method of photoeradication of cellular and acellular organisms including the steps of providing a surface acting agent containing benzalkonium chloride in association with a cellular or acellular organism, the surface acting agent disorienting a membrane structure so that said membrane no longer functions as an effective osmotic barrier； providing a photosensitive material in association with the cellular or acellular organism； and applying light in association with the cellular or acellular organism to cause a disruption of the organism. The method according to the present invention may be utilized in invitro and invivo treatment protocols for infections, sterilization procedures, cancer cell eradication, virus and fungus eradication, spore eradication, and biofilm organism eradication. Additional aspects of the invention include particular combinations of photosensitive materials and surfactants for use in photodynamic therapies.
