Dependence of Radachlorin fluorescence lifetime on solution pH and localization in Hela cells

Variations of Radachlorin fluorescence lifetime with pH in PBS solutions have been studied. As shown, an increase in pH resulted in the fluorescence lifetime rise. FLIM-assisted experiments on Radachlorin fluorescence lifetimes in living HeLa cells demonstrated dependence of the lifetime on intracellular localization of Radachlorin molecules. Recorded variations of Radachlorin fluorescence lifetime within intracellular area were about 15-20%.