Correlative super-resolution fluorescence and electron cryo-microscopy based on cryo-SOFI.

Area of Science:

• Cell Biology
• Microscopy Techniques
• Biophysics

Background:

• Correlative super-resolution fluorescence and electron microscopy (cryo-CLEM) is an emerging technique for high-resolution cellular imaging.
• High laser intensities required for super-resolution imaging pose a risk of specimen devitrification in cryogenic conditions.

Purpose of the Study:

• To introduce and validate cryogenic super-resolution optical fluctuation imaging (Cryo-SOFI) as a method to overcome laser-induced devitrification in super-resolution cryo-CLEM.
• To demonstrate the compatibility of Cryo-SOFI with standard cryogenic electron microscopy (cryo-EM) workflows.

Main Methods:

• Implementation of Cryo-SOFI in a standard cryogenic fluorescence microscope.
• Utilizing low laser intensities for super-resolution image reconstruction.
• Compatibility assessment with standard sample preparation protocols for cryo-EM.

Main Results:

• Cryo-SOFI successfully reconstructs super-resolution images at significantly reduced laser intensities.
• The method prevents devitrification of biological specimens under cryogenic conditions.
• Cryo-SOFI integrates seamlessly into existing cryogenic fluorescence microscopy setups.

Conclusions:

• Cryo-SOFI is a viable and accessible method for enabling super-resolution cryo-CLEM.
• This technique mitigates the risk of laser-induced damage, expanding the possibilities for high-resolution imaging of biological samples.
• The ease of implementation makes Cryo-SOFI a valuable tool for the cell biology community.