Advantages and Possibilities of Fluorescence-Based Methods for the Visualization of Apoptosis and Autophagy in Human Tumor Cells in vitro

The possibilities of using fluorescence-based analytical methods and their advantages for visualization and identification of the type of programmed cell death in human tumor cells exposed to flavonoids have been analyzed in experiments in vitro. HeLa cervical cancer cells and A498 kidney carcinoma cells were used as the objects of the study, and exposure to the flavonoid-containing extract of common hedgehyssop (Gratiola officinalis L.) was tested as the experimental treatment. The following fluorescence-based techniques were used: the “live and dead” test with double staining by propidium iodide and acridine orange and double staining with annexin and propidium iodide. Autophagy induction was confirmed by fluorescence-based tests implemented in a Muse cell analyzer with a Muse Autophagy LC3-Antibody Based Kit. The use of double staining with acridine orange and propidium iodide fluorescent dyes in the “live and dead” test and comparison with phase contrast microscopy enables the visualization of apoptotic body and autophagosome formation processes in the cells and can, therefore, be used as a method of screening assessment of the efficiency of various chemotherapy drugs.