Quantitative Analysis of Apoptosis and Necrosis in Live Cells Using Flow Cytometry.

Apoptosis and necrosis are the two sides of the cell death penumbra. Apoptosis is a well-studied model of cell death wherein the cell destroys itself employing a predefined form of active signaling without the release of soluble cytoplasmic contents to the external environment. Compared to apoptosis, necrosis is a nonspecific form of sudden cell death in response to an invasive external stimulus which in turn is devoid of active programmed intracellular signaling leading to the sudden release of the soluble cellular contents consequent to the rupture of the cell membrane.

Mitochondria targeted redox GFP reveals time and dose dependent onset and progression of mitochondrial oxidation with diverging cell death decisions during photodynamic therapy.

Background: Photodynamic therapy (PDT) is a successful cancer treatment modality. In vitro, in vivo, and clinical studies with different photosensitizers reveal diverging cell fates, including apoptosis, necrosis, autophagy, and non-specific forms of cell death. The mode of action and efficacy of PDT is mediated through free radical generation and is highly dependent on diverse variables such as nature, dose, metabolism of photosensitizer, irradiation energy, and irradiation cycle.