Аннотация:Monitoring of variations in morphological characteristics of cultured HeLa cells after photodynamic treatment with Radachlorin photosensitizer is performed by means of digital holographic microscopy. The observed dose- dependent post-treatment variations of phase shift evidence threshold effect of photodynamic treatment and allow for distinguishing between necrotic or apoptotic pathways of cell death. Results obtained by holographic microscopy were confirmed by means of far-field optical microscopy and confocal fluorescence microscopy with commonly used test assays.