Magnify is a universal molecular anchoring strategy for expansion microscopy

Area of Science:

• Biophysics
• Cell Biology
• Microscopy

Background:

• Expansion microscopy (ExM) enables nanoscale imaging by physically magnifying biological specimens.
• Conventional ExM requires chemical anchoring steps to link biomolecules to the hydrogel matrix.
• There is a need for simplified ExM protocols that preserve diverse biomolecules without complex anchoring.

Purpose of the Study:

• To introduce Magnify, a novel expansion microscopy strategy.
• To demonstrate a mechanically robust hydrogel that retains nucleic acids, proteins, and lipids without prior anchoring.
• To achieve high-resolution nanoscale imaging of various biological specimens.

Main Methods:

• Development of a mechanically sturdy, water-swellable hydrogel for specimen embedding.
• Expansion of biological specimens up to 11 times their original size.
• Imaging of expanded specimens using conventional and super-resolution optical fluctuation imaging techniques.

Main Results:

• Magnify successfully expands biological specimens without requiring a separate anchoring step.
• Achieved effective resolutions of ~25 nm on conventional microscopes and ~15 nm with super-resolution optical fluctuation imaging.
• Demonstrated Magnify's versatility on diverse samples, including mouse brain, human kidney, and lung organoids.

Conclusions:

• Magnify offers a simplified and effective approach to expansion microscopy.
• The method provides deep insights into nanoscopic subcellular structures.
• Magnify enhances the accessibility of high-resolution imaging for biological research.