MRI: Development of Zernike Phase Contrast For Biological Electron Microscopy

MRI：生物电子显微镜泽尼克相差的发展

• 批准号: 1040543
• 负责人: Holger Mueller
• 金额: $ 97.71万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1040543&HistoricalAwards=false
• 关键词: MRI; Development; Zernike; Phase; Contrast

This Major Research Instrumentation award funds the development of a novel Zernike laser phase plate for cryo-TEM at University of California-Berkeley. In Zernike phase contrast microscopy, a quarter-wave plate in the focal plane of the object lens shifts the phase of the undiffracted part of the beam to provide optimal conversion of phase modulations into image contrast. The new laser phase plate will allow researchers to operate TEMs in an optimal phase-contrast mode for indefinite periods of time. Compared with defocused bright field method, the contrast in the imaging of biological macromolecules and supramolecular structures could be as much as ten times greater. Moreover, the possibility to make a tiny focus and the possibility to tune it optically makes it possible to image lower spatial frequencies and offers greater flexibility than with microfabricated phase plates. This new phase contrast system will be used to investigate problems in molecular and cell biology that are out of the reach of existing techniques in electron microscopy, x-ray crystallography, or multi-dimensional NMR spectroscopy. Finally, we anticipate additional applications in fundamental physics, e.g., developing an optical dipole trap for atoms and molecules of almost any species, with the ability to trap even room-temperature samples. The results of the development effort will be broadly disseminated through abstracts and peer reviewed publications, as well as by active participation of students and faculty at professional meetings.

该主要研究仪器奖资助了加州大学伯克利分校用于低温TEM的新型Zernike激光相位板的开发。 在Zernike相衬显微镜中，在物透镜的焦平面中的四分之一波片移动光束的未衍射部分的相位，以提供相位调制到图像对比度的最佳转换。 新的激光相位板将允许研究人员在无限期的时间内以最佳相衬模式操作TEM。与散焦明场方法相比，在生物大分子和超分子结构的成像中，对比度可以提高十倍。此外，制作微小焦点的可能性和光学调谐的可能性使得可以成像较低的空间频率，并提供比微加工相位板更大的灵活性。这种新的相衬系统将用于研究分子和细胞生物学中的问题，这些问题超出了电子显微镜，X射线晶体学或多维NMR光谱学中现有技术的范围。 最后，我们预计在基础物理学中的其他应用，例如，开发一种光学偶极阱，几乎可以捕获任何种类的原子和分子，甚至可以捕获室温样品。开发工作的结果将通过摘要和同行评审的出版物，以及学生和教师在专业会议的积极参与广泛传播。