Developments Of In Situ Cryo-Electron Tomography For Biological Applications

The study and structural analysis of biological macromolecular complexes are crucial for a comprehensive understanding of their function and biological significance. The cryo-electron microscopy has become the mainstream technology for providing information about the structure and distribution of macromolecules in biology. In addition, the advancement of hardware and software in rencet years has further improved the effectiveness of cryo-electron microscopy, making it more accurate and faster to analyze various biological structures and proteins. However, for biological systems, proteins or macromolecular complexes are in a complex physiological environment, so in situ detection of the 3D biological structures is crucial for biological system and structural biology. As a powerful technology, cryo-electron tomography can rely on the intrinsic contrast of frozen samples to identify the structure of biological macromolecules directly without marking, and can perform 3D imaging with nano-resolution in their native environment. In this review, we summerized the methods of sample preparation and technical aspects relevant for cryo-electron tomography as well as the biological applications from isolated macromolecular complexes to entire cells and tissues.