Spectroscopic measurements of the transmembrane potential difference

Other electrochromic membrane probes of note include, merocyanine 540 used to study the transmembrane potential in liver mitochondria but some problems are also evident. Although membrane potential measurements in mitochondria have been identified in the foregoing section, many of these strategies are generic and hold for plasma membranes of (eg.) neurones or other excitable tissues, as does the following in which more cellular studies are emphasised. 

Overall, measurements of transmembrane potential differences in living cells is fairly well established with the methods fairly reliable and robust. These mostly take on two strategies either utilising electrodes or optical tools such as fluorescence to record the potential differences (Vm or Ai/ ) based on electrochromism or probe accumulation according to the Nernst equation (5.3). 

---