Zernike Phase Contrast Cryo-Electron Tomography of Bacteria and Viruses
نویسندگان
چکیده
Cryo-electron tomography (cryo-ET) is currently the only method available through which pleomorphic biological specimens are imaged to produce three-dimensional (3D) structures at ~2 to 10 nm resolution [1]. There remain challenges associated with imaging intact bacteria and pleomorphic viruses by cryo-ET. In particular, investigators cope with the low contrast of cryo-preserved, unstained specimens and the requirement for low dose imaging in order to limit radiation damage to the specimen. Zernike phase contrast (ZPC) transmission electron microscopy (TEM) was developed to overcome these and other complications [2]. Here we present results showing the success of using ZPC technologies for cryo-ET investigations of bacterial cells and pleomorphic viruses.
منابع مشابه
Artifact Correction for Zernike Phase-Plate Cryo-Electron Tomography
In cryo-electron microscopy (cryo-EM), vitreously frozen biological specimens can tolerate only a limited electron dose for imaging. Therefore, cryo-EM micrographs display weak contrast and a poor signal-to-noise ratio. This limits data interpretability and prevents efficient application of cryo-EM to a wider range of biological problems. Continued efforts have been invested in imaging methods ...
متن کاملHigh Throughput Fabrication Process of a Zernike Phase Plate
In transmission electron microscopy (TEM) for biological and polymer samples, it is difficult to image with high contrast, since they are mostly composed of light elements and have similar density. One solution to enhance the contrast is utilization of phase contrast microscopy, which is realized in optical microscopy. Accordingly, many types of phase plates for electron microscopy have been pr...
متن کاملPhase Contrast Subtomogram Averaging at Sub-nm Resolution
Phase contrast imaging is a powerful technique that can increase the signal to noise ratio and contrast of the phase objects in their native and frozen hydrated state. The improved contrast is as a result of the phase shift between the unscattered and the scattered electron beams. The so called Volta phase plate (VPP) is a newly developed thin film phase plate which has advantages compared to t...
متن کاملZernike phase contrast cryo-electron microscopy and tomography for structure determination at nanometer and subnanometer resolutions.
Zernike phase contrast cryo-electron microscopy (ZPC-cryoEM) is an emerging technique that is capable of producing higher image contrast than conventional cryoEM. By combining this technique with advanced image processing methods, we achieved subnanometer resolution for two biological specimens: 2D bacteriorhodopsin crystal and epsilon15 bacteriophage. For an asymmetric reconstruction of epsilo...
متن کاملAutomated Cryo-tomography and Single Particle Analysis with a New Type of Phase Plate
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 hind...
متن کامل