Project 1: Development of Multi-element 2D and 3D Imaging of Single Cells and Tissues Using Laser Ablation Inductively Coupled Plasma Time-of-Flight Mass Spectrometry (LA-ICP-TOF-MS)
Trace metals are crucial for physiological processes with highly regulated trafficking, localization, and homeostasis, where interruptions or slight variations lead to cell and tissue dysfunction and ultimately to disease. In order to fully understand the spatiotemporal interplay of metals in biological systems, multiple imaging techniques are required that balance sensitivity, selectivity, and spatial resolution to provide a complete understanding of these fundamental processes. The capabilities of LA-ICP-MS complement SXFM and PAM imaging, namely: low detection limits (µg/g), full elemental mass spectrum coverage, high spatial resolution, limited sample preparation, wide linear dynamic range, and ability to analyze whole tissue sections relatively rapidly (minutes to hours). However, significant improvements in sample standardization, system integration, detector sensitivity, ablation cell design, and data analysis are needed to make this a robust high-throughput technique capable of providing multi-element 3D maps of cells and tissues in real time.
Research of the technology will include:
Project 2: Increasing the Sensitivity and Throughput of Synchrotron-Based X-Ray Fluorescence Microscopy (XFM) for Single Cell and Tissue Analysis
Scanning x-ray fluorescence microscopy (SXFM) works by using a high brightness x-ray beam, an optic to produce either a micrometer or a sub-100 nm focused spot through which a specimen is scanned, and an x-ray fluorescence detector (such as a silicon drift diode-type energy-dispersive spectrometer or EDS detector) to collect photons emitted at characteristic x-ray fluorescence lines at energies well approximated by the Bohr model of the atom. This requires a large flux of coherent x-rays (which is 109 photons/sec today) in the x-ray nanofocus spot, and this is achievable only when one uses one of the nation’s high brightness synchrotron radiation sources. At incident photon energies of 15 keV, the brightest of these today is the Advanced Photon Source (APS) at nearby Argonne National Lab, which represents about a $1B investment primarily by the US Department of Energy, which is now planning a $700M upgrade to increase beam brightness 100-1000 fold. To fully utilize this advance, we urge NIH to make an investment in the specialized technologies for cell and tissue studies.
Research of the technology will include:
Project 3: Photoacoustic Microscopy for Dynamic Imaging of Inorganic Ion Fluxes in Vivo
Since the introduction of PAM by Prof. Zhang and colleagues in 2006, PAM is only technology available that can image intrinsic optical absorption in three dimensions with a high spatial resolution. A PAM image reflects the volumetric optical absorption distribution in a tissue. Since the scattering of ultrasonic waves is two orders of magnitude weaker than that of optical scattering, information about the source of the acoustic wave can be easily attained in deep tissue. Such one-way optical scattering grants PAM a larger penetration depth compared to confocal microscopy using an identical optical irradiation wavelength. PAM employs a confocal geometry, in which the optical illumination and the ultrasonic detection are focused on the same spatial volume to achieve localized measurement and high signal-to-noise ratio (SNR).
Research of the technology will include:
Project 1: Development of Multi-element 2D and 3D Imaging of Single Cells and Tissues Using Laser Ablation Inductively Coupled Plasma Time-of-Flight Mass Spectrometry (LA-ICP-TOF-MS)
Trace metals are crucial for physiological processes with highly regulated trafficking, localization, and homeostasis, where interruptions or slight variations lead to cell and tissue dysfunction and ultimately to disease. In order to fully understand the spatiotemporal interplay of metals in biological systems, multiple imaging techniques are required that balance sensitivity, selectivity, and spatial resolution to provide a complete understanding of these fundamental processes. The capabilities of LA-ICP-MS complement SXFM and PAM imaging, namely: low detection limits (µg/g), full elemental mass spectrum coverage, high spatial resolution, limited sample preparation, wide linear dynamic range, and ability to analyze whole tissue sections relatively rapidly (minutes to hours). However, significant improvements in sample standardization, system integration, detector sensitivity, ablation cell design, and data analysis are needed to make this a robust high-throughput technique capable of providing multi-element 3D maps of cells and tissues in real time.
Research of the technology will include:
Project 2: Increasing the Sensitivity and Throughput of Synchrotron-Based X-Ray Fluorescence Microscopy (XFM) for Single Cell and Tissue Analysis
Scanning x-ray fluorescence microscopy (SXFM) works by using a high brightness x-ray beam, an optic to produce either a micrometer or a sub-100 nm focused spot through which a specimen is scanned, and an x-ray fluorescence detector (such as a silicon drift diode-type energy-dispersive spectrometer or EDS detector) to collect photons emitted at characteristic x-ray fluorescence lines at energies well approximated by the Bohr model of the atom. This requires a large flux of coherent x-rays (which is 109 photons/sec today) in the x-ray nanofocus spot, and this is achievable only when one uses one of the nation’s high brightness synchrotron radiation sources. At incident photon energies of 15 keV, the brightest of these today is the Advanced Photon Source (APS) at nearby Argonne National Lab, which represents about a $1B investment primarily by the US Department of Energy, which is now planning a $700M upgrade to increase beam brightness 100-1000 fold. To fully utilize this advance, we urge NIH to make an investment in the specialized technologies for cell and tissue studies.
Research of the technology will include:
Project 3: Photoacoustic Microscopy for Dynamic Imaging of Inorganic Ion Fluxes in Vivo
Since the introduction of PAM by Prof. Zhang and colleagues in 2006, PAM is only technology available that can image intrinsic optical absorption in three dimensions with a high spatial resolution. A PAM image reflects the volumetric optical absorption distribution in a tissue. Since the scattering of ultrasonic waves is two orders of magnitude weaker than that of optical scattering, information about the source of the acoustic wave can be easily attained in deep tissue. Such one-way optical scattering grants PAM a larger penetration depth compared to confocal microscopy using an identical optical irradiation wavelength. PAM employs a confocal geometry, in which the optical illumination and the ultrasonic detection are focused on the same spatial volume to achieve localized measurement and high signal-to-noise ratio (SNR).
Research of the technology will include: