Resolution enhancement for low-temperature scanning microscopy by cryo-immersion.

Area of Science:

• Cryogenic microscopy
• Optical imaging techniques

Background:

• Achieving high-resolution imaging under cryogenic conditions is crucial for various scientific fields.
• Conventional confocal microscopy faces challenges with resolution degradation at low temperatures.

Purpose of the Study:

• To develop a straightforward method for enhancing confocal scanning microscope resolution at cryogenic temperatures.
• To enable high-resolution imaging at 160 K comparable to ambient conditions.

Main Methods:

• Utilized a high numerical aperture (NA = 1.25) microscope objective.
• Employed 1-propanol as a low-freezing-point immersion fluid.
• Implemented sample scanning instead of beam scanning.
• Housed the objective and sample within a cryostat's inner chamber to minimize thermal distortions.

Main Results:

• Achieved imaging resolution at 160 K that is comparable to ambient conditions.
• Demonstrated enhanced image quality using a commercially available microscope objective.
• Successfully reduced distortions caused by temperature gradients.

Conclusions:

• The developed method offers a simple and effective way to enhance cryogenic confocal microscopy resolution.
• This technique is a significant advancement for cryo high-resolution microscopy.
• Facilitates progress in correlative light and electron cryo microscopy (cryoCLEM).