Hare, DJ, Kysenius, K, Paul, B, Knauer, B, Hutchinson, RW, O'Connor, C, Fryer, F, Hennessey, TP, Bush, AI, Crouch, PJ & Doble, PA 2017, 'Imaging Metals in Brain Tissue by Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry (LA-ICP-MS).', Journal of Visualized Experiments, no. 119, pp. 1-8.View/Download from: Publisher's site
Metals are found ubiquitously throughout an organism, with their biological role dictated by both their chemical reactivity and abundance within a specific anatomical region. Within the brain, metals have a highly compartmentalized distribution, depending on the primary function they play within the central nervous system. Imaging the spatial distribution of metals has provided unique insight into the biochemical architecture of the brain, allowing direct correlation between neuroanatomical regions and their known function with regard to metal-dependent processes. In addition, several age-related neurological disorders feature disrupted metal homeostasis, which is often confined to small regions of the brain that are otherwise difficult to analyze. Here, we describe a comprehensive method for quantitatively imaging metals in the mouse brain, using laser ablation - inductively coupled plasma - mass spectrometry (LA-ICP-MS) and specially designed image processing software. Focusing on iron, copper and zinc, which are three of the most abundant and disease-relevant metals within the brain, we describe the essential steps in sample preparation, analysis, quantitative measurements and image processing to produce maps of metal distribution within the low micrometer resolution range. This technique, applicable to any cut tissue section, is capable of demonstrating the highly variable distribution of metals within an organ or system, and can be used to identify changes in metal homeostasis and absolute levels within fine anatomical structures.
Hare, DJ, Fryer, F, Paul, B, Bishop, DP & Doble, PA 2016, 'Characterisation of matrix-based polyatomic interference formation in laser ablation-inductively coupled plasma-mass spectrometry using dried micro-droplet ablation and its relevance for bioimaging', ANALYTICAL METHODS, vol. 8, no. 41, pp. 7552-7556.View/Download from: Publisher's site
Bishop, DP, Clases, D, Fryer, F, Williams, E, Wilkins, S, Hare, DJ, Cole, N, Karst, U & Doble, PA 2016, 'Elemental bio-imaging using laser ablation-triple quadrupole-ICP-MS', JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, vol. 31, no. 1, pp. 197-202.View/Download from: Publisher's site
Bishop, DP, Hare, DJ, Fryer, F, Taudte, RV, Cardoso, BR, Cole, N & Doble, PA 2015, 'Determination of selenium in serum in the presence of gadolinium with ICP-QQQ-MS', ANALYST, vol. 140, no. 8, pp. 2842-2846.View/Download from: Publisher's site
Bishop, DP, Hare, DJ, de Grazia, A, Fryer, F & Doble, PA 2015, 'Speciation and quantification of organotin compounds in sediment and drinking water by isotope dilution liquid chromatography-inductively coupled plasma-mass spectrometry', ANALYTICAL METHODS, vol. 7, no. 12, pp. 5012-5018.View/Download from: Publisher's site
Lear, J, Hare, DJ, Fryer, F, Adlard, PA, Finkelstein, DI & Doble, PA 2012, 'High-resolution elemental bioimaging of Ca, Mn, Fe, Co, Cu, and Zn employing LA-ICP-MS and hydrogen reaction gas', Analytical Chemistry, vol. 84, no. 15, pp. 6707-6714.View/Download from: Publisher's site
Imaging of trace metal distribution in tissue sections by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is typically performed using spatial resolutions of 30 µm2 and above. Higher resolution imaging is desirable for many biological applications in order to approach the dimensions of a single cell. The limiting factor for increasing resolution is sensitivity, where signal-to-noise ratios are poor due to inherent background spectral interferences and reduced sample volume with decreasing laser beam diameter. Several prominent spectral interferences are present for a number of biologically relevant isotopes, including the 40Ar16O+ spectral interference on 56Fe+. We examined if H2 as a reaction gas could improve the analytical performance of imaging experiments for a range of masses with spectral interferences. At low (<1 mL min1) H2 flow rates, greater spectral interference due to H+ adducts was observed for 55Mn, 57Fe, and 59Co. At higher flow rates of up to 3 mL H2 per minute, the spectral interferences were reduced leading to improvement in limits of analysis for masses with O- and N-based polyatomic interferences. Enhanced sensitivity with the reaction cell allowed construction of high resolution (6 µm2) imaging of 56Fe in the mouse brain that approached the dimensions of single cells.
Austin, CE, Fryer, FI, Lear, J, Bishop, DP, Hare, DJ, Rawling, T, Kirkup, L, McDonagh, AM & Doble, PA 2011, 'Factors Affecting Internal Standard Selection For Quantitative Elemental Bio-Imaging Of Soft Tissues By LA-ICP-MS', Journal of Analytical Atomic Spectrometry, vol. 26, no. 7, pp. 1494-1501.View/Download from: Publisher's site
Element response variations under different laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) operating conditions were investigated to identify important factors for selecting an internal standard (IS) for quantitative elemental bi
Hare, DJ, Tolmachev, S, James, A, Bishop, DP, Austin, CE, Fryer, FI & Doble, PA 2010, 'Elemental bio-imaging of thorium, uranium, and plutonium in tissues from occupationally exposed former nuclear workers', Analytical Chemistry, vol. 82, no. 8, pp. 3176-3182.View/Download from: Publisher's site
Internal exposure from naturally occurring radionuclides (including the inhaled long-lived actinides 232Th and 238U) is a component of the ubiquitous background radiation dose (National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States; NCRP Report No. 160; NCRP: Bethesda, MD, 2009). It is of interest to compare the concentration distribution of these natural ?-emitters in the lungs and respiratory lymph nodes with those resulting from occupational exposure, including exposure to anthropogenic plutonium and depleted and enriched uranium. This study examines the application of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) to quantifying and visualizing the mass distribution of uranium and thorium isotopes from both occupational and natural background exposure in human respiratory tissues and, for the first time, extends this application to the direct imaging of plutonium isotopes. Sections of lymphatic and lung tissues taken from deceased former nuclear workers with a known history of occupational exposure to specific actinide elements (uranium, plutonium, or americium) were analyzed by LA-ICPMS.
Hare, DJ, Haarburger, D, Austin, CE, Fryer, FI, Grimm, R, Reedy, BJ, Scolyer, RA, Thompson, JF & Doble, PA 2009, 'Elemental bio-imaging of melanoma in lymph node biopsies', The Analyst, vol. 134, no. 3, pp. 450-453.View/Download from: Publisher's site
The spatial distribution of trace elements in human lymph nodes partially infiltrated by melanoma cells was determined by elemental bio-imaging. Imaging of 31P within the nodal capsule and normal lymph node tissue showed a clear demarcation of the tumour boundary, with a significant decrease in relative 31P concentration within the tumour. The location of the tumour boundary was confirmed by haematoxylin and eosin staining of serial sections and observation by light microscopy. Further enhancement of the tumour boundary was achieved by imaging the 31P/34S ratio. 31P/66Zn ratio images showed a decreasing ratio beyond the tumour boundary that extended into peritumour normal lymph node tissue.