Approaches to Alter Particles Distribution in cryo-electron Microscopy Sample Preparation

With the development of equipment and software, cryo electronic microscopy (cryoEM) was wildly used in structural biology to investigate biomolecular structure at atomic resolution. However, the sample quality is a barrier to pursuing higher resolution, including uneven distribution problems, heterogonous problems, and preferred orientation problems. Electron cryotomography (cryoET), a special application of cryoEM, have the advantage to resolve the 3D structure with a series of 2D tilting image at the same location, which is good to study the sample distribution in the thin ice layer. In this thesis, sample distribution was visualized by cryoET, and surfactant fluorinated fos choline 8 was used to manipulate the sample distribution. Besides, the principle underlying these problems were addressed based on calculation. Surface tension was the primary explanation for these problems