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Updated: Aug 27, 2025
Simultaneous Measurement of Mitochondrial Calcium and Mitochondrial Membrane Potential in Live Cells by Fluorescent Microscopy
Published on: January 24, 2017
Mitochondria targeted dual-fluorescent probe for bio-imaging viscosity and F- with different fluorescence signals
Sukhvinder Dhiman1, Rasdeep Kour2, Satwinderjeet Kaur2
1Department of Chemistry, Center for Advanced Studies, Guru Nanak Dev University, Amritsar 143005, India.
Abstract:
The F- ion and viscosity both affect the physiological state of mitochondria and to the best of our knowledge no fluorescent probe is reported for the dual detection of mitochondrial viscosity and F- ion through different signals. DMAS-Si is weakly red fluorescent due to free intramolecular rotation between dimethylaminophenyl and pyridinium moieties and PET from silyloxy to the pyridinium moiety. In viscous medium (glycerol 90 %), the rotation is restricted and 18-fold increase in red-fluorescence (λem 637 nm) is observed. On reaction with F- ion, the desilylations followed by release of quinone-methide from DMAS-Si gives intense green fluorescence (λem 515 nm) due to formation of DMAS. DMAS-Si can detect as low as 50 nM F-. DMAS-Si shows good permeability to HeLa cells and preferably targets mitochondria. It has been used for imaging of increased viscosity in mitochondria of HeLa cells in the presence of nystatin through red fluorescence and exogenous F- ion by appearance of green fluorescence.
Insights
This study introduces DMAS-Si, a novel fluorescent probe for simultaneously detecting mitochondrial viscosity and fluoride ions. It offers distinct red and green fluorescence signals for dual imaging in cells.
Area of Science:
- Biochemistry
- Cell Biology
- Analytical Chemistry
Background:
- Mitochondrial function is influenced by both viscosity and fluoride (F-) ion concentration.
- Existing fluorescent probes lack the capability for simultaneous dual detection of these parameters.
Purpose of the Study:
- To develop and characterize a novel fluorescent probe, DMAS-Si, for the dual detection of mitochondrial viscosity and F- ion.
- To demonstrate the probe's utility in live-cell imaging.
Main Methods:
- Synthesis and characterization of the DMAS-Si probe.
- Spectroscopic analysis to determine fluorescence changes in response to viscosity and F- ion.
- Cellular imaging experiments using HeLa cells.
Main Results:
- DMAS-Si exhibits environment-sensitive red fluorescence (λem 637 nm) that increases 18-fold in viscous media due to restricted intramolecular rotation.
- Reaction with F- ions triggers desilylation, leading to intense green fluorescence (λem 515 nm) from the formed DMAS.
- The probe successfully imaged increased mitochondrial viscosity and exogenous F- ions in HeLa cells.
Conclusions:
- DMAS-Si is a novel, dual-signal fluorescent probe for simultaneous detection of mitochondrial viscosity and F- ions.
- The probe demonstrates excellent cell permeability and mitochondrial targeting capabilities.
- This tool enables advanced imaging of mitochondrial physiological states.
