Volumetric Chemical Imaging of Cell Metabolism by Stimulated Raman Projection

在化学系化学测量和成像项目以及分子和细胞生物科学系系统和合成生物学项目的支持下，波士顿大学的郑教授正在开发一种成像工具，以微米分辨率，三维（3D）方式和高速检查化学物质。 程教授设想他开发的技术可用于监测细胞中的小生物分子，并了解它们的原位代谢。 程教授计划将这项技术开发出来后，通过商业化的方式提供给其他用户。 除了与学生合作进行项目外，郑教授还为本科生提供暑期研究机会。 他还组织了一个为期2天的研讨会，向学生讲授无标记光谱成像，并开发了一个关于化学显微镜概念的实验室模块。体积成像能够对3D复杂系统进行定量和全局测量。它允许定量的分子在整个体积的标本，并已被证明是无价的细胞代谢，脑功能和发育生物学的研究。对体积成像的最简单方法是通过轴向方向上的光学切片。这种方法需要紧密聚焦的激光束和良好的轴向切片能力。用于体积成像的一种方法是通过断层扫描，其中从样本周围的许多不同角度收集图像。然后可以使用角度相关图像重建3D信息。程教授开发了一种基于贝塞尔光束的受激拉曼投影（SRP）显微镜和断层扫描，用于高速体积化学成像。SRP方法是建立在这样的概念上的，即检测信号是SRS强度沿输入贝塞尔光束的瑞利长度沿着的积分，该贝塞尔光束在长距离内保持其沿沿着的焦点。与高斯光束SRS显微镜相比，贝塞尔光束SRP显微镜能够在2D扫描中量化3D体积的总化学成分。郑教授计划将为期两天的无标记光谱成像研讨会与波士顿大学光子学中心的年度研讨会结合起来，向参加研讨会的约250名科学家介绍无标记化学成像的创新。 此外，郑教授还利用波士顿大学的CityLab与初中和高中的学生和教师建立联系。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry and the Systems and Synthetic Biology program in the Division of Molecular and Cellular Biosciences, Professor Cheng at Boston University is developing an imaging tool to examine chemical species at a micron resolution, in a three-dimensional (3D) fashion, and at high speed. Professor Cheng envisions the technique he develops can be used to monitor small biomolecules in cells and understand their metabolism in situ. Professor Cheng plans to make the technique, once developed, available to other users through commercialization. In addition to working with students on the project, Professor Cheng also provides summer research opportunities to undergraduate students. He also organizes a 2-day workshop to teach students about label-free spectroscopic imaging and develops a lab module on the concept of chemical microscopy. Volumetric imaging enables quantitative and global measurements of a 3D complex system. It allows quantitation of molecules in the whole volume of a specimen, and has proven to be invaluable in the studies of cell metabolism, brain function, and developmental biology. The simplest way to image a volume is through optical sectioning in the axial direction. Such a method requires tightly focused laser beams and good axial sectioning capability. One approach for volumetric imaging is through tomography, in which images are collected from many different angles around the sample. The 3D information can be then reconstructed using the angle-dependent images. Professor Cheng develops a Bessel-beam-based stimulated Raman projection (SRP) microscopy and tomography for high-speed volumetric chemical imaging. The SRP method is built upon the concept that the detected signal is an integration of SRS intensity along the Rayleigh length of the input Bessel beams, which remain their focuses along axial direction for a long distance. Compared to the Gaussian beam SRS microscopy, the Bessel beam SRP microscopy is able to quantify the total chemical compositions of a 3D volume in a 2D scan. Professor Cheng plans to integrate a two-day workshop on label-free spectroscopic imaging with the annual symposium of the Boston University's Photonics Center to present innovations in label-free chemical imaging to ~250 scientists attending this symposium. Furthermore, Professor Cheng leverages Boston University's CityLab to connect with middle and high school students and teachers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.