Preparing Frozen-Hydrated Protein-Nucleic Acid Assemblies for High-Resolution Cryo-EM Imaging

Area of Science:

• Structural biology
• Biophysics
• Biochemistry

Background:

• Cryo-electron microscopy (cryo-EM) enables high-resolution structure determination.
• Effective sample preparation is crucial for successful cryo-EM.
• Grid preparation remains a significant challenge in cryo-EM workflows.

Purpose of the Study:

• To present detailed protocols for preparing electron microscopy grids.
• To address common challenges in sample preparation for cryo-EM.
• To facilitate the study of protein-nucleic acid complexes using cryo-EM.

Main Methods:

• Detailed protocols for negative-stain grid preparation.
• Step-by-step procedures for cryo-grid preparation.
• Application of protocols to protein-nucleic acid complexes.

Main Results:

• Streamlined protocols for reproducible grid preparation.
• Strategies for achieving optimal particle monodispersity.
• Methods for controlling sample concentration and ice thickness.

Conclusions:

• Optimized grid preparation protocols enhance cryo-EM data quality.
• These methods are effective for protein-nucleic acid complexes.
• Standardized protocols can overcome bottlenecks in structural biology.