A tunable refractive index matching medium for live imaging cells, tissues and model organisms

Area of Science:

• Microscopy and imaging science
• Biomedical optics
• Cell biology

Background:

• Refractive index mismatches in light microscopy cause spherical aberrations, limiting imaging depth and resolution.
• Current optical clearing techniques are effective but restricted to fixed biological samples.

Purpose of the Study:

• To introduce a non-toxic medium supplement for refractive index matching in live specimens.
• To enhance image quality and penetration depth in live-imaged samples.

Main Methods:

• Utilized Iodixanol as a non-toxic medium supplement.
• Applied the supplement to various live biological models including cell cultures, planarians, zebrafish, and organoids.
• Performed light microscopy to assess image quality and penetration.

Main Results:

• Demonstrated successful refractive index matching in live specimens using Iodixanol.
• Significantly improved image quality, including resolution and penetration depth.
• Validated the technique across diverse live samples: primary cell cultures, planarians, zebrafish, and human cerebral organoids.

Conclusions:

• Iodixanol is an effective and non-toxic optical clearing agent for live specimens.
• This method overcomes limitations of traditional optical clearing, enabling high-quality live imaging.
• The technique offers broad applicability for advanced microscopy of living biological systems.