Mitochondria and apoptosis: Functional studies on membrane potential (Δψ)

Apoptosis is a phenomenon of crucial importance in all multicellular, living organisms: it is involved in several physiological and pathological phenomena which incluse embryogenesis, differentiation, development of the immune system, as well as control of cell growth, cancerogenesis, viral production. The assumption that apoptosis is an active process led to study mitochondria, the main intracellular source of energy, which is produced in form of ATP. It is reasonable to hypothesize that, at least in early apoptotic phases, cells have to maintain a good driving force for ATP synthesis, and, consequently, a high mitochondrial membrane potential (Δψ), that becomes a reliable mirror of the capacity to synthesize ATP and, in general, of mitochondrial membrane functionality. In this article, the use of different fluorescent probes for the analysis of Δψ is discussed paying a particular attention for JC-1, that is considered the golden standard for this type of measure.