Fluorescence microscopy image analysis
automation - time series - physiology

TMRM PMPI technique - mitochondrial assay bis-oxonol and tetramethylrhodamine methyl ester (TMRM) Mitochondrial membrane potential assay
Absolute and Unbiased ΔψM Assay

   Commonly used mitochondrial membrane potential (ΔψM) assays often lead to data misinterpretation. This is because all of these probes are influenced by multiple properties of cells other than ΔψM.

  Our technology is based on biophysical modeling of probe behavior to back-calculate ΔψM and ΔψP from time courses of fluorescence intensities. This enables absolute millivolts readout, and an unbiased comparison of different samples, accounting for geometric, binding and ΔψP effects.

The Theory
Theory of the TMRM/PMPI technique

How absolute millivolts are calculated

See how effects of ΔψP, cell and mitochondrial geometry and fluorescence background accounted for to calculate mV values.

In Practice
Membrane Potential Calibration Wizard

The Membrane Potential Calibration Wizard

This interactive dialog works hand in hand with the provided protocol to calibrate potentials without theoretical knowledge.

See the technology in publications
  • In human stem cells (14)
  • In rat neurons (17)
  • In human and rodent β-cells (26,31,40)
Image Analyst MKII protocols


Protocols explaining experimental design, microscopy setup and image analysis

Protocols area
Development of the unbiased, absolute mitochondrial membrane potential assay has been supported by: SBIR/STTR  NIDA