The present invention is based on the discovery that electroporation of a photosensitive agent in a cell and subsequent activation of the agent provides more effective killing of the electroporated cell than cells exposed to a photosensitive agent alone. The invention provides a method and apparatus for inhibiting cell growth or enhancing cell death. The method includes providing a photosensitive agent to a cell; applying an electric pulse to the cell of a sufficient strength and duration to electroporate the cell with the photosensitive agent; and applying light of an activatable wavelength to the cell thereby activating the agent and inhibiting cell growth or enhancing cell death.