Fluorescence Imaging of Cell Membrane Potential: From Relative Changes to Absolute Values

Area of Science:

• Cellular and Molecular Biology
• Biophysics

Background:

• Cell membrane potential is vital for cellular processes like neuronal activity and cell cycle progression.
• Current methods often measure relative membrane potential changes using fluorescent voltage indicators.
• These methods do not always account for fluorescence variations unrelated to voltage, limiting long-term or absolute measurements.

Purpose of the Study:

• To review techniques enabling the measurement of absolute cell membrane potential.
• To address the need for corrected signals in long-term biological process investigations.
• To highlight methods that exclude voltage-independent fluorescence alterations.

Main Methods:

• Review of existing scientific literature on membrane potential measurement techniques.
• Analysis of methods utilizing organic dyes and genetically-encoded voltage indicators.
• Focus on techniques that allow for the evaluation of absolute membrane potential values.

Main Results:

• Existing techniques primarily measure relative membrane potential changes.
• A gap exists in methods for accurately determining absolute membrane potential, especially for long-term studies.
• Correction for voltage-independent fluorescence factors is necessary for precise measurements.

Conclusions:

• Accurate measurement of absolute cell membrane potential is essential for understanding complex biological processes.
• Further development and application of techniques that correct for non-voltage-dependent fluorescence are needed.
• This review consolidates knowledge on advanced membrane potential measurement strategies.