A Hierarchical Etched Grid for Correlative Chemical Imaging

Area of Science:

• Biological imaging
• Materials science
• Analytical chemistry

Background:

• Correlative microscopy combining synchrotron X-ray fluorescence (SXRF) and optical imaging is crucial for mapping elemental distributions in biological samples.
• Accurate spatial correlation between these techniques is challenging, limiting data interpretation and precision.
• Existing methods, like using tissue architecture or electron microscopy grids, have limitations in resolution and can introduce interfering elements.

Purpose of the Study:

• To present a novel finder grid system for enhanced spatial correlation in SXRF correlative microscopy.
• To overcome limitations of conventional registration methods for biological tissue analysis.
• To improve accuracy and data interpretation in multimodal imaging studies.

Main Methods:

• Developed a hierarchically patterned fiducial system etched onto quartz substrates using femtosecond laser ablation.
• Created two finder grid formats: microgrid and nanogrid designs.
• Demonstrated utility with human brain tissue for region-of-interest (ROI) relocalization and correlative workflows.

Main Results:

• The etched quartz finder grid enables improved correlation across SXRF, optical imaging, and histology over various length scales.
• This method surpasses conventional registration techniques by avoiding XRF signal interference from fiducial markers.
• Facilitates rapid and reproducible ROI relocalization and alignment across different instruments, especially with sparse fiducial markers.

Conclusions:

• The novel quartz finder grid offers a robust solution for precise spatial correlation in SXRF correlative microscopy.
• This technique enhances the reliability of elemental mapping in biological tissues.
• The approach is adaptable for broader applications in multimodal imaging and analysis.