Mitochondrial membrane potential
The mitochondrial membrane potential, mtMP, is the electric part of the protonmotive force, ΔpH+.
Δψ = ΔpH+ – ΔµH+ / F
mtMP or Δψ is the potential difference across the mitochondrial (mt) inner membrane, expressed in the electrical unit volt [V].
mt-Membrane potential can either be measured in the NextGen-O2k Fluo and O2k-Fluo fluorometrically by using the fluorophores TMRM, Safranin, or Rhodamine 123, or potentiometrically with the O2k-TPP+ ISE-Module, which can be applied with any O2k configuration (Series B or higher), by using the ion reporter TPP+. All mentioned ion indicator molecules are cations which inhibit respiration, making it essential carry out respiratory controls to evaluate the effect of the indicator.
Meet the expert
Krumschnabel G, Eigentler A, Fasching M, Gnaiger E (2014) Use of safranin for the assessment of mitochondrial membrane potential by high-resolution respirometry and fluorometry. Methods Enzymol 542:163-81. -»Bioblast link«
Sumbalova Z, Gnaiger E (2015) High-resolution measurement of mitochondrial membrane potential and respiration – comparison of potentiometric and fluorometric methods. Abstract MiP2015. -»Bioblast link«