Sizing Marine Microbes With Scattered Light

近几十年来，海洋科学中最重要的革命之一是对微生物在海洋和全球生态中所起的基本作用的描述。然而，尽管它们具有重要意义，但被认为是海洋生态系统重要特征的种群大小谱的评估一直存在问题。超过90%的海洋微生物无法培养，这一事实使问题更加复杂。在过去的十年里，贾菲博士一直在研究下一代仪器，这些仪器有望利用可见光来表征海洋微生物。新仪器的中心思想利用了这样一个事实，即以非前向角度散射的光包含了物体中最小空间结构的信息。由于这种光不是传统光学显微镜成像的光的主要组成部分，传统图像的特征对小于~ 1µm的结构不敏感。虽然更先进的方法可以超过这一标准，但将它们用于常规方式来确定海洋微生物种群的大小并不简单。PI申请资金用于开发一种新型光学显微镜，该显微镜可用于表征比光波长更小的粒子。一个成功的证明，光学显微镜可以用来系统地表征亚波长粒子的常规方式描述这里将是一个重要的里程碑在光学方法的发展。因此，其他研究领域，如细胞生物学，将受益于这种方法，因为亚波长细胞结构的常规推断对细胞分选、理解细胞结构以及细胞病理学具有重要影响。更广泛的影响：所提出的光学系统和分析方法将广泛影响海洋微生物生态学、生物光学海洋学，并有可能扩展到其他领域，如生物医学。该项目通过对博士生的支持，特别有助于研究生教育/培训。还概述了高中申请的推广。但最重要的是，潜在的项目成果可以用于广泛的其他生物和海洋物理领域，这些领域采用光学方法来处理非常小的物体。

One of the most significant revolutions in the marine sciences in recent decades has been the characterization of the fundamental role that microbes play in both oceanic and global ecology. However, despite their significance, the assessment of population size spectra, considered to be an important character of marine ecosystems, has been problematic. The issue is compounded by the fact that more than 90% of marine microbes cannot be cultured. Over the last decade, Dr. Jaffe has been working on a next generation of instruments that show promise to characterize marine microbes using visible light. The central idea of the new instrument takes advantage of the fact that the light that is scattered at the non-forward angles contains information about the smallest spatial structures in the object. Since this light is not a major component of the light imaged in conventional optical microscopy, features of conventional images are insensitive to structures smaller than ~ 1 µm. Although more advanced methods can exceed this criteria, their use in a routine manner to size marine microbial populations is not straightforward. The PI requests funding to develop a new type of light microscope that can be used to characterize particles that are smaller than the wavelength of light. A successful demonstration that light microscopy can be used to systematically characterize sub-wavelength particles in the routine manner described here would be a significant milestone in the development of optical methods. As such, other fields of inquiry, such as cellular biology, would benefit from this methodology as the routine inference of sub wavelength cell structure has important ramifications for cell sorting, understanding cellular structure, as well as cell pathology.Broader Impacts:The proposed optical system and analysis methods could broadly impact marine microbial ecology, bio-optical oceanography, and potentially extend to other fields such as biomedicine. The project specifically contributes to graduate education/training through support of a PhD student. Outreach to high-school applications is also outlined. But most importantly, the potential project outcomes can be used in a broad range of other biological and marine-physics fields which employ optical methods to deal with very small objects.