Analysis of mitochondrial morphology and function with novel fixable fluorescent stains

Area of Science:

• Cell Biology
• Mitochondrial Biology
• Biochemistry

Background:

• Investigating mitochondrial morphology and function is crucial for understanding cellular processes.
• Previous limitations in photostable, mitochondrion-specific stains hindered detailed analysis in fixed and permeabilized cells.

Purpose of the Study:

• To introduce and validate novel mitochondrion-specific fluorescent stains, CMXRos and H2-CMXRos.
• To assess the photostability, retention, and specificity of these dyes in fixed cells.
• To demonstrate their utility in analyzing mitochondrial fine structure and function.

Main Methods:

• Live cell staining with CMXRos and H2-CMXRos dyes.
• Assessment of dye photostability compared to Rhodamine 123.
• Evaluation of dye retention after formaldehyde fixation and acetone permeabilization.
• Co-localization studies with antibodies to cytochrome c oxidase subunit I.
• Confocal microscopy for suborganellar localization.
• Flow cytometry to assess response to mitochondrial membrane potential changes.

Main Results:

• CMXRos and H2-CMXRos exhibit greater photostability than Rhodamine 123.
• Mitochondrial staining is preserved after fixation and permeabilization.
• Dyes specifically localize to mitochondria, confirmed by co-localization with cytochrome c oxidase.
• Confocal imaging reveals distinct suborganellar localization patterns.
• Staining intensity correlates with mitochondrial membrane potential and function.
• CMXRos allows for multi-feature cell morphology evaluation.

Conclusions:

• CMXRos and H2-CMXRos are effective, photostable mitochondrial stains retained in fixed cells.
• These dyes facilitate detailed analysis of mitochondrial morphology and suborganellar organization.
• CMXRos serves as a valuable tool for monitoring mitochondrial function and integrating with other cellular imaging.