TIME-RESOLVED CONFOCAL FLUORESCENCE MICROSCOPY OF PORPHYRINS FOR PHOTOTHERAPY

The application of a novel time-resolved confocal fluorescence microsp ectrometer to studies of the distribution and speciation of porphyrin photosensitizers in rat C6 cerebral glioma cells is described. The ins trument combines a mode-locked argon ion laser excitation source with time-correlated single photon counting fluorescence detection and has sub-micron spatial and sub-nanosecond temporal resolution, The porphyr ins studied were haematoporphyrin derivative (HpD), haematoporphyrin I X (HP), porphyrin c (Pc) and the tetrakiscarborane carboxylate ester o f 2,4-(alpha, beta-dihydroxyethyl) deuteroporphyrin IX (BOPP), From th e heterogeneous emission observed in vitro, assignments and spatial lo cation of various porphyrin species are proposed.