Absolute spectroscopic determination of cross-membrane potential

Area of Science:

• Biophysics
• Cell Biology
• Spectroscopy

Background:

• Spectroscopic methods, including absorption and fluorescence, are established for studying membrane electrical properties noninvasively.
• Traditional fluorescence techniques primarily track potential changes in excitable membranes, not absolute values, and lack single-cell resolution.

Purpose of the Study:

• To review novel spectroscopic methods for overcoming limitations in membrane potential measurement.
• To enable absolute membrane potential determination and single-cell/organelle analysis.

Main Methods:

• Nernstian dyes for fluorescence microscopy enabling single-cell/organelle potential determination.
• Dual-wavelength ratiometric recording with membrane-staining dyes for single-cell potential measurement.
• Resonance Raman probes offering a spectroscopic method with an internal standard for absolute potential measurement.

Main Results:

• Nernstian dyes allow for fluorescence microscopic determination of membrane potential in single cells and organelles.
• Dual-wavelength ratiometry enables single-cell membrane potential field measurements.
• Resonance Raman probes provide absolute membrane potential measurements using an internal standard.

Conclusions:

• The reviewed methods significantly advance the capability to measure membrane potential with high precision.
• These techniques offer solutions for absolute potential determination and single-cell analysis, expanding research possibilities.