New insights to primary photodynamic effects--Singlet oxygen kinetics in living cells.

Abstract The kinetics of chemical singlet oxygen quencher consumption inside living cells during low dose illumination was revealed via time resolved singlet oxygen luminescence detection. Deviations of the measured data from the common theoretical model for 1 O 2 kinetics forced the authors to consider a one-dimensional diffusion model for description of the kinetics of singlet oxygen generated by membrane localized photosensitizers. Our observations reconcile seemingly contradictory reports presenting different values for the efficiency of singlet oxygen interaction with cells.