ZnPc [(OCH2CH2)3 OH]4 (ZnTEPc) was compared with zinc-tetra-sulfo-phthalocyanine (ZnTSPc) in their photochemical properties and ability to sensitize cells to red light in vitro. Both Pc were added to F-10 medium and incubated with HeLa cells for 30min. After wash-out of the dye, they were exposed to red light. Cells were damaged only by ZnTSPc. ZnTSPc has a longer triplet life time. It generates much singlet oxygen and is incorporated more to cells.
