Cryo-Electron Three-Dimensional Imaging of Soft Materials
Cryogenic transmission electron microscopy (Cryo-TEM) is used to characterize labile systems that are not allowed in room temperature electron microscopy due to a high vapor pressure. Although soft materials are characterized with cryo-TEM, the original structure of the sample is lost. This is because a three-dimensional (3D) structure is projected to a two-dimensional (2D) image. These researchers used a single-particle construction method to visualize conventional 2D images to 3D microstructures with a high resolution. They are exploring an electron tomography method to construct 3D images. This method combines a series of 2D images that are collected at different angles and constructs a 3D image. To do this, mathematical algorithms of cross-correlation and an image alignment must be combined and solved simultaneously. Computer calculations are indispensable in structure characterization study and allow researchers to understand the structure as electron microscopy collect and process the data. Such information will help reinterpret typical 2D images of soft materials and their functionality.