STED-TEM Correlative Microscopy Leveraging Nanodiamonds as Intracellular Dual-Contrast Markers

Area of Science:

• Biophysics
• Microscopy
• Nanotechnology

Background:

• Correlative light and electron microscopy (CLEM) requires dual-contrast markers for accurate multimodal image registration.
• Existing labeling methods face challenges in achieving precise correlation and compatibility with various sample types.

Purpose of the Study:

• To introduce fluorescent nanodiamonds (FNDs) as versatile dual-contrast probes for CLEM.
• To demonstrate the utility of FNDs for high-resolution imaging and precise image correlation in STED/confocal and TEM.

Main Methods:

• Development and application of FNDs as fluorescent and electron-dense labels.
• Utilized SuperTomo software for automatic image registration and correlation.
• Performed correlative microscopy experiments on live cells, fixed cells, and test samples.

Main Results:

• FNDs successfully served as dual-contrast labels, enabling precise image correlation between fluorescence and TEM.
• FNDs demonstrated robustness, surviving TEM sample preparation and allowing fluorescence imaging before or after TEM.
• Successful application of FNDs in high-resolution STED/confocal and TEM correlative microscopy experiments.

Conclusions:

• Fluorescent nanodiamonds represent a novel and effective solution for dual-contrast labeling in correlative microscopy.
• FNDs facilitate accurate multimodal image registration and are compatible with diverse sample preparations and imaging workflows.