The first use of the photodynamic activity of chemical compounds and visible light against microorganisms was published at the beginning of the last century. Hermann von Tappeiner et al. reported that the observed toxic effect in the presence of the light was not attributed to heat. In 1904, von Tappeiner coined the term “photodynamic reaction” for the reaction of light with a non-toxic dye13, 14. After a long hiatus, in the 1970’s photo dynamic therapy (PDT) began to be explored for the selective destruction of malignancies15. Common features of tumor cells and microorganisms are high proliferation and active metabolisms. Therefore, if microorganisms can accumulate different photosensitizers, photodynamic inactivation of them might be effective16.