The photoinactivation of three different human cancer cell lines, HeLa, neuroblastoma and U87 and antimicrobial activities against Gram-positive (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa) by protoporphyrin IX and protoporphyrin– dopamine conjugate were examined. The antimicrobial activities were screened by optical density measurement at 600 nm. Also, the cytotoxicity and proliferation assays were performed with LDH measurements at 490 nm and WST-1 assays at 450 nm, respectively, with and without irradiation.