A Method for Generation of Synthetic 2D and 3D Cryo-EM Images

Abstract

Cryo-electron microscopy (cryo-EM) is widely used in structural biology for resolving 3D models of particles with Angstrom resolution. The most popular techniques for such high-resolution model reconstruction are single-particle cryo-EM and cryo-electron tomography (cryo-ET). The cornerstone of both techniques is the registration of images: 2D images in cryo-EM and 3D images in cryo-ET. There are several registration methods for 2D and 3D cryo-EM images; however, it is hard to evaluate these methods due to the lack of ground truth for real data. Moreover, evaluation of image registration methods on real data is complicated by a high level of noise. In this paper, we propose image synthesis methods for generating realistic 2D single-particle cryo-EM images and 3D cryo-ET subtomogram images. The proposed algorithms model the artifacts typical of the real EM image acquisition pipeline: EM-specific noise, missing wedge effect, 2D projection, and contrast transfer function. We also present some examples of the 2D and 3D synthetic images generated.