Diffusion of acridine molecules to a genetic site in living cells

A method which constitutes the measurement of induced photosensitized reaction at a specified site in living cells by illumination of short duration was developed to study a dynamic aspect of the interaction between small molecules and a specific cellular site. By using this method it was demonstrated that the diffusion of acridine orange molecules, starting outside of the cell, to a particular site of nuclear DNA could be measured in yeast cells. The temperature dependence of the rate constant suggests that the viscosity of cytoplasm is not a major barrier in this process.