Automated Cryo-tomography and Single Particle Analysis with a New Type of Phase Plate

Abstract

Recent years have shown an increased interest in the development and use of phase plates in cryo-EM. The oldest and the most productive type of phase plate is the carbon film Zernike phase plate [1]. It has been successfully used in cryo-tomography [2] and single particle analysis applications [3]. Despite its good performance the Zernike phase plate has a few pitfalls. One major practical hindrance is its short lifetime [4]. Typically within 10 days after being installed into the microscope its performance deteriorates to the point where it has to be exchanged. Another disadvantage of the Zernike phase plate is that it produces fringes around high-contrast features in the image, such as lipid membranes, support film edges etc [5]. Despite its shortcomings the Zernike phase plate has been the main motivation and experience generator in the last years.