Solid immersion microscopy images cells under cryogenic conditions with 12 nm resolution

Area of Science:

• Cell Biology
• Microscopy
• Biophysics

Background:

• Super-resolution fluorescence microscopy is vital for understanding cell structure and function, offering 20-30 nm resolution.
• Current resolution limits hinder imaging of dynamic macromolecular machinery within cells.
• Cryogenic conditions enhance fluorophore brightness and preserve cellular ultrastructure better than chemical fixation.

Purpose of the Study:

• To improve the resolution of fluorescence microscopy under cryogenic conditions.
• To overcome limitations of existing high numerical aperture objectives for cryogenic imaging.
• To enable high-resolution imaging of macromolecular machinery in cells.

Main Methods:

• Development and application of a low-cost super-hemispherical solid immersion lens (superSIL).
• Imaging of cellular samples under cryogenic conditions using a basic setup.
• Utilizing superSIL for multicolor imaging and exploring total-internal-reflection fluorescence (TIRF) microscopy.

Main Results:

• Achieved 12 nm resolution in cells under cryogenic conditions, the best reported for simple setups.
• Demonstrated multicolor imaging capabilities.
• Paved the way for cryogenic TIRF imaging of mammalian cells.

Conclusions:

• SuperSIL microscopy provides a straightforward method for achieving unprecedented resolution in cellular imaging.
• This technique significantly advances the study of cellular ultrastructure and molecular mechanisms.
• Opens new avenues for high-resolution live-cell imaging under physiological conditions.