[On measurements of mitochondrial transmembrane potential by fluorescent probes]

It is common thought that rhodamine, cyanine, and some other fluorescent dyes are specific potential-dependent and that they allow of quantitatively measuring the transmembrane potential in mitochondria and cells. However, a critical analysis of the experimental data shows that this statement is only a supposition. In reality, widely used fluorescent probes, such as merocyanine 540, Dis-C3-(5). Safranin O, 8-anilino-1-naphthalene sulfonate and others are poorly linked to the native mitochondria and react only a little to their energization or disconnection. It can be concluded that calculations of the magnitude of the transmembrane potential of the inner mitochondrial membrane in response to the addition of succinate, ATP or dinitrophenol by fluorescence of these probes are incorrect.