Expanding boundaries - a cell biologist's guide to expansion microscopy

Area of Science:

• Biophysics
• Cell Biology
• Microscopy

Background:

• Conventional light microscopy is limited by the diffraction of light, hindering the visualization of subcellular structures.
• Super-resolution microscopy offers higher resolution but often requires specialized and expensive instrumentation.
• There is a need for accessible methods to achieve nanoscale resolution in biological imaging.

Approach:

• Expansion microscopy (ExM) physically enlarges fixed biological samples embedded in a swellable hydrogel.
• Isotropic expansion of the hydrogel physically separates labeled molecules, increasing effective resolution.
• This method leverages conventional microscopy, making nanoscale imaging more accessible.

Key Points:

• ExM achieves nanoscale resolution by physically expanding the sample, overcoming the diffraction limit.
• The technique relies on sample preparation and hydrogel chemistry, not advanced optics.
• It can be combined with super-resolution techniques for even greater detail.
• ExM is reproducible and has broad applications across the life sciences.

Conclusions:

• Expansion microscopy provides a powerful and accessible approach to achieving high-resolution imaging in biology.
• Its ease of use and reproducibility facilitate its adoption in diverse research settings.
• ExM represents a significant advancement in visualizing cellular organization at the nanoscale.