High resolution imaging of biological structures and their changes induced by different agents such as drugs are commonly performed by confocal and electron microscopy. The past decade has witnessed an emersion of the atomic force microscopy (AFM) from solid-state physics into cell biology and even medical applications. For these reasons, we used this relatively new microscopic technique to study the morphology of cell lines. We imaged the cells by atomic force microscopy before and after the photodynamic therapy (PDT) using the photosensitizer ClAlPcS(2). We also compared the impact of the photosensitizer in combination with silymarin antioxidant on cancer and non-cancer cell lines by measuring the kinetic production of reactive oxygen species (ROS). PDT was induced by LED source with total irradiation dose of 15 J cm(-2) and SDT was induced by therapeutic ultrasound with frequency of 1 MHz, intensity 2 W cm(-2) and time of exposition 10 min. The results show ROS kinetic production within the cells during PDT, sonodynamic therapy (SDT) and modification of morphological features investigated by AFM. The combination of a sensitizer and the specific light source can lead to the loss of surface rigidity and eventually to dramatic changes of the cell shape, which we can study by AFM.