Related Experiment Video
Updated: Jul 4, 2025
Specific Labeling of Mitochondrial Nucleoids for Time-lapse Structured Illumination Microscopy
Published on: June 4, 2020
Long-Chain Fluorescent Probe for Straightforward and Nondestructive Staining Mitochondria in Fixed Cells and Tissues
Qiuhua Hao1, Xiuquan He2, Kang-Nan Wang1
1State Key Laboratory of Crystal Materials, Advanced Medical Research Institute, Shandong University, Jinan 250100, P. R. China.
Abstract:
Normally, small-molecule fluorescent probes dependent on the mitochondrial membrane potential (MMP) are invalid for fixed cells and tissues, which limits their clinical applications when the fixation of pathological specimens is imperative. Given that mitochondrial morphology is closely associated with disease, we developed a long-chain mitochondrial probe for fixed cells and tissues, DMPQ-12, by installing a C12-alkyl chain into the quinoline moiety. In fixed cells stained with DMPQ-12, filament mitochondria and folded cristae were observed with confocal and structural illumination microscopy, respectively. In titration test with three major phospholipids, DMPQ-12 exhibited a stronger binding force to mitochondria-exclusive cardiolipin, revealing its targeting mechanism. Moreover, mitochondrial morphological changes in the three lesion models were clearly visualized in fixed cells. Finally, by DMPQ-12, three kinds of mitochondria with different morphologies were observed in situ in fixed muscle tissues. This work breaks the conventional concept that organic fluorescent probes only stain mitochondria with normal membrane potentials and opens new avenues for comprehensive mitochondrial investigations in research and clinical settings.
Insights
Researchers developed DMPQ-12, a novel fluorescent probe for fixed cells and tissues. This probe visualizes mitochondrial morphology in fixed samples, overcoming limitations of traditional probes dependent on mitochondrial membrane potential (MMP).
Area of Science:
- Biochemistry
- Cell Biology
- Medical Imaging
Background:
- Traditional fluorescent probes for mitochondria rely on mitochondrial membrane potential (MMP), limiting their use in fixed cells and tissues.
- Fixation is crucial for pathological specimen analysis, creating a need for probes functional in fixed samples.
- Mitochondrial morphology is a key indicator of cellular health and disease progression.
Purpose of the Study:
- To develop a novel long-chain mitochondrial fluorescent probe, DMPQ-12, for visualizing mitochondria in fixed cells and tissues.
- To elucidate the targeting mechanism of DMPQ-12.
- To demonstrate the utility of DMPQ-12 in observing mitochondrial morphology in disease models and clinical samples.
Main Methods:
- Synthesis of DMPQ-12 by incorporating a C12-alkyl chain into a quinoline moiety.
- Staining of fixed cells and tissues with DMPQ-12.
- Microscopy techniques (confocal and structural illumination) for imaging mitochondrial morphology.
- Phospholipid binding assays to determine the probe's targeting specificity.
- Visualization of mitochondrial changes in three lesion models and fixed muscle tissues.
Main Results:
- DMPQ-12 successfully stained mitochondria in fixed cells, revealing filamentous structures and folded cristae.
- The probe demonstrated specific binding to cardiolipin, indicating a mitochondria-exclusive targeting mechanism.
- Mitochondrial morphological alterations associated with disease were clearly visualized in fixed cells.
- Three distinct mitochondrial morphologies were observed in situ within fixed muscle tissues using DMPQ-12.
Conclusions:
- DMPQ-12 overcomes the limitations of MMP-dependent probes, enabling mitochondrial visualization in fixed samples.
- The probe's specificity for cardiolipin ensures accurate mitochondrial targeting.
- This work expands the application of fluorescent probes for comprehensive mitochondrial studies in both research and clinical settings.
