Related Experiment Video
Updated: Feb 6, 2026
06:26
Monitoring Dynamic Changes In Mitochondrial Calcium Levels During Apoptosis Using A Genetically Encoded Calcium Sensor
Published on: April 1, 2011
24.4K
Tracking mitochondrial dynamics during apoptosis with phosphorescent fluorinated iridium(iii) complexes
Chen Zhang1, Kangqiang Qiu2, Chaofeng Liu1
1MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, P. R. China. ceschh@mail.sysu.edu.cn.
Dalton Transactions (Cambridge, England : 2003)
|August 18, 2018
Summary
Researchers developed novel fluorinated iridium(iii) complexes to track mitochondrial dynamics during apoptosis. These phosphorescent probes show high specificity for mitochondria, offering a new tool for studying cell death.
Area of Science:
- Chemical Biology
- Biochemistry
- Cell Biology
Background:
- Mitochondria play a crucial role as the control centers of apoptosis (programmed cell death).
- Understanding mitochondrial dynamics during apoptosis is vital for studying cell fate.
- Existing mitochondrial trackers may lack specificity or exhibit cytotoxicity.
Purpose of the Study:
- To design and synthesize novel phosphorescent iridium(iii) complexes for tracking mitochondrial dynamics.
- To investigate the impact of fluorination on the photophysical properties of these complexes.
- To evaluate the suitability of these complexes as mitochondrial probes in live and fixed cells.
Main Methods:
- Synthesis of four fluorinated iridium(iii) complexes (Ir1-Ir4).
- Characterization of photophysical properties (emission maxima, quantum yields, lifetimes).
- Assessment of photostability, cytotoxicity, cellular localization, and specificity in HeLa cells.
Main Results:
- Tuning of emission maxima, quantum yields, and lifetimes by ligand fluorination.
- Complexes exhibited excellent photostability and low cytotoxicity.
- Cationic and lipophilic nature led to mitochondrial localization via an energy-independent pathway.
- Ir1-Ir4 demonstrated high specificity for mitochondria, outperforming commercial trackers.
Conclusions:
- The developed iridium(iii) complexes are effective tools for tracking mitochondrial dynamics during apoptosis.
- Fluorination provides a method to tune the properties of these mitochondrial probes.
- These complexes offer a promising alternative for mitochondrial imaging with high specificity and low toxicity.
Related Concept Videos
01:23Photoluminescence: Fluorescence and Phosphorescence
3.9K
Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds.
A pair of electrons in a...
A pair of electrons in a...
3.9K
01:43Electron Transport Chain: Complex III and IV
9.3K
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
9.3K
01:30Apoptosis
15.2K
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size...
15.2K
01:26Variables Affecting Phosphorescence and Fluorescence
1.5K
Fluorescence and phosphorescence are essential phenomena in fields like analytical chemistry, biological imaging, and materials science, where they detect molecular properties and visualize cellular structures. Understanding the variables that influence these luminescent behaviors is crucial for maximizing accuracy and efficiency in their applications. These variables can broadly be grouped into chemical structure, solvent properties, and external conditions, each playing a distinct role in...
1.5K
01:25Fluorescence and Phosphorescence: Instrumentation
1.6K
Fluorometers and spectrofluorometers are two types of instruments used for measuring molecular fluorescence. These instruments differ in how they select excitation and emission wavelengths and the type of light sources they utilize. Fluorometers use absorption interference filters to choose excitation and emission wavelengths. The excitation source in a fluorometer is typically a low-pressure mercury vapor lamp that emits intense lines distributed throughout the ultraviolet and visible regions.
1.6K
02:59Animal Mitochondrial Genetics
9.3K
Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
9.3K