I am studying the membrane potential of non-excitable lung adenocarcinoma cells by flow cytometry using the fluorescent dye DiBAC (3)4. I have no trouble observing relative differences in the shape, mean and mode of the histogram. However, I would like to calculate the absolute resting membrane potential in mV.
Some authors describe a method by which patch clamp tests are used to standardize and find a relationship between the membrane potential and the fluorescence readings. But unfortunately we do not have a patch clamp system in our lab.
Hi Salvador,
A piece of answer: you could maybe have a look at the approach used to measure the membrane potential of mitochondria in living cells:
Quantitative measurement of mitochondrial membrane potential in cultured cells: calcium-induced de- and hyperpolarization of neuronal mitochondria http://www.ncbi.nlm.nih.gov/pubmed/22495585
You can likely adapt the method to measure the membrane potential of cells.
Hope this helps. Norbert
You can also use fluorescent dyes and measure it with sprectrofluorometry. The calibration is done by adding an ionophore and sequential additions of known concentrations of KCl. You can read the method with more detail here:
https://www.researchgate.net/publication/261743916_Membrane_Hyperpolarization_during_Human_Sperm_Capacitation
Best, regards.
Oscar
Article Membrane Hyperpolarization during Human Sperm Capacitation.
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