Synchrotron-based Imaging Strategies to Visualize (trace) Metals
Trace elements are critical for the development and function of all lifeforms. Metals, such as manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn), or the metalloid selenium (Se) serve as co-factors in catalytic reactions, as stabilizers for proteins, or in dynamic signalling events in cellular processes. Methods to visualize these elements greatly contributed to our current understanding of cellular homeostasis as well as disease mechanisms that are associated with changes in trace element metabolism.
Synchrotron-based X-ray fluorescent microscopy (XFM) is an outstanding tool to determine elemental distributions in biological specimen with high spatial resolution and trace-level sensitivity. XFM is a scanning technique that utilizes the intrinsic fluorescence properties unique to each element.
Exciting advancements in beamline instrumentation such as improved optics and detectors have led to increases in spatial resolution to ~10 nm and better sensitivities which in turn leads to decreased data acquisition time and lower detection limits. Today, investigators have a choice of powerful synchrotron sources on almost all continents, offering experimental setups for a wide range of projects, typically accessible to the community free of charge, based on proposals.
Perhaps even more exciting, numerous synchrotrons either have recently upgraded, are upgrading, or plan to upgrade in the near future to new storage ring technology that brings significantly increased X-ray brightness. This brightness increase directly translates into improved XFM performance.
The goal of this themed issue is to provide a cross-section of methods and applications for XFM. As such we include publications about detailed sample preparation and techniques, tool development to contextualize trace elemental distribution, data analysis toolkits, as well as examples of applications of XFM at varying resolutions for 2-dimensional or 3-dimensional imaging.
Histatin-5 (Hist-5) is an antimicrobial peptide found in human saliva that functions to defend the oral cavity from microbial infections, such as those caused by the fungal pathogen Candida albicans ( C. albicans ). Hist-5 can bind Cu in multiple oxidation states, Cu 2+ and Cu + in vitro , and ...
The abandoned Allchar Mine in the Republic of North Macedonia is a globally unique deposit with the highest known grades of thallium (Tl) and arsenic (As) mineralization. We aimed to determine the distribution of As and Tl in whole dehydrated shoots of the three Viola taxa using synchrotron ...
Iron is accumulated symplastically in kelp in a non-ferritin core that seems to be a general feature of brown algae. Microprobe studies show that Fe binding depends on tissue type. The sea is generally an iron-poor environment and brown algae were recognized in recent years for having a unique, ...
Synchrotron-based micro-X-ray fluorescence analysis (µXRF) is a nondestructive and highly sensitive technique. However, element mapping of rare earth elements (REEs) under standard conditions requires care, since energy-dispersive detectors are not able to differentiate accurately between REEs ...
Pityrogramma calomelanos and Pteris vittata are cosmopolitan fern species that are the strongest known arsenic (As) hyperaccumulators, with potential to be used in the remediation of arsenic-contaminated mine tailings. However, it is currently unknown what chemical processes lead to uptake of As in ...
The movement of metals through the environment links together a wide range of scientific fields: from earth sciences and geology as weathering releases minerals; to environmental sciences as metals are mobilized and transformed, cycling through soil and water; to biology as living things take up ...
The ornate spiny rock lobster, Panulirus ornatus , is an attractive candidate for aquaculture. The larval stages of spiny lobsters, known as phyllosoma, are complex with many developmental stages. Very little is known about the inorganic element composition of phyllosoma. In this study, a novel ...
All organisms, fundamentally, are made from the same raw material, namely the elements of the periodic table. Biochemical diversity is achieved by how these elements are utilized, for what purpose, and in which physical location. Determining elemental distributions, especially those of trace ...
X-ray fluorescence microscopy (XFM) has become a widely used technique for imaging the concentration and distribution of metal ions in cells and tissues. Recent advances in synchrotron sources, optics, and detectors have improved the spatial resolution of the technique to <10 nm with attogram ...
Understanding the nanoscale chemical speciation of heterogeneous systems in their native environment is critical for several disciplines such as life and environmental sciences, biogeochemistry, and materials science. Synchrotron-based X-ray spectromicroscopy tools are widely used to understand the ...
Visualizing the endogenous distribution of elements within plant organs affords key insights in the regulation of trace elements in plants. Hyperaccumulators have extreme metal(loid) concentrations in their tissues, which make them useful models for studying metal(loid) homeostasis in plants. ...
Scanning X-ray fluorescence (XRF) tomography provides powerful characterization capabilities in evaluating elemental distribution and differentiating their inter- and intra-cellular interactions in a three-dimensional (3D) space. Scanning XRF tomography encounters practical challenges from the ...
The molecular biology and genetics of the Ni–Cd–Zn hyperaccumulator Noccaea caerulescens has been extensively studied, but no information is yet available on Ni and Zn redistribution and mobilization during seed germination. Due to the different physiological functions of these elements, and their ...
Macadamia integrifolia and M. tetraphylla , unlike M. ternifolia , are known for their edible nuts. All three species over-accumulate the trace metal nutrient manganese (Mn) in their shoots. This study seeks to examine tissue- and cellular-level distribution of Mn and other plant nutrients in the ...
Iron is a key micronutrient for ocean phytoplankton, and the availability of iron controls primary production and community composition in large regions of the ocean. Pennate diatoms, a phytoplankton group that responds to iron additions in low-iron areas, can have highly variable iron contents, ...
Synchrotron-based X-ray fluorescence microscopy is a flexible tool for identifying the distribution of trace elements in biological specimens across a broad range of sample sizes. The technique is not particularly limited by sample type and can be performed on ancient fossils, fixed or fresh tissue ...
Globally, the majority of Ni hyperaccumulator plants occur on ultramafic soils in tropical regions, and the genus Phyllanthus , from the Phyllanthaceae family, is globally the most represented taxonomical group. Two species from Sabah (Malaysia) are remarkable because Phyllanthus balgooyi can ...
Hemorrhagic transformation of ischemic stroke has devastating consequences, with high mortality and poor functional outcomes. Animal models of ischemic stroke also demonstrate the potential for hemorrhagic transformation, which complicates biochemical characterization, treatment studies, and ...
During neurodevelopment, neurons form growth cones, F-actin rich extensions located at the distal end of the neurites. Growth cones allow dendrites and axons to build synaptic connections through a process of neurite guidance whose mechanisms have not been fully elucidated. Calcium is an important ...
