scholarly journals STANDARDS FOR ELECTRON PROBE MICROANALYSIS OF BIOLOGIC SPECIMENS

1972 ◽  
Vol 20 (9) ◽  
pp. 710-715 ◽  
Author(s):  
G. M. LEHRER ◽  
C. BERKLEY
Keyword(s):  
Tissue Section ◽  
Elemental Analysis ◽  
Electron Microprobe ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Regression Curve ◽  
X Ray ◽  
Tissue Sections ◽  
Freeze Dried ◽  
Carbon Coated

A procedure is described for the preparation and application of gelatin standards in the quantitative elemental analysis of microscopic portions of tissue sections in the electron microprobe x-ray spectrometer. Ten to fifteen per cent gelatin solutions containing varying concentrations of the elements to be measured are quick-frozen in capsules, sectioned in a cryostat at the same thickness as the tissue and freeze-dried. Standard sections are mounted with each tissue section, carbon-coated and analyzed simultaneously. Concentrations of the elements in portions of the tissue as small as 10–12 liters are then determined directly from a regression curve or equation derived from the standards.

Trauma causes heterogeneous compositional shifts in spinal cord

1992 ◽  
Vol 50 (2) ◽  
pp. 1594-1595
Author(s):  
Lyle G. Walsh ◽  
William B. Greene
Keyword(s):  
Spinal Cord ◽  
Electron Probe ◽  
Healthy People ◽  
Spinal Cord Trauma ◽  
Liquid Propane ◽  
X Ray ◽  
Cold Stage ◽  
Freeze Dried ◽  
Carbon Coated

Each year spinal cord trauma causes thousands of otherwise healthy people to be permanently disabled. In most cases, the axonal tracts are not mechanically severed. Instead, unknown mechanisms cause a progressive segmental necrosis. In this study, we use electron probe x-ray microanalysis, EPMA, to examine the composition of the dorsal axons and myelin 6 hours after mild and moderate trauma in order to identify the subcellular changes induced by trauma. Laminectomies were performed on anesthetized rats and sham, 6 g-cm or 20 g-cm trauma was delivered and the wound closed. Six hours after trauma the rats were again anesthetized, the dura was removed and the spinal cord was frozen in situ with a 100 psi jet of super-cooled liquid propane. Cryosections, 200 nm thick, were cut at -120°C and placed on carbon coated formvar covered folding copper grids. Samples were freeze dried and analyzed within an Hitachi H-7000 STEM on a Be tipped, GATAN, analytical cold stage with a 2-4 nA, 125 KeV beam.

Low-cost system for electron probe microanalysis based on a personal computer

1990 ◽  
Vol 48 (2) ◽  
pp. 158-159
Author(s):  
Margaret C. Foster ◽  
Albert J. Saubermann
Keyword(s):  
Data Acquisition ◽  
Personal Computer ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Low Cost ◽  
Personal Computers ◽  
X Ray ◽  
Freeze Dried ◽  
The Cost ◽  
Data Acquisition And Processing

The development of personal computers increases the options available for electron probe microanalysis. Hardware and software are now available for personal computers which make it feasible to use them to acquire, process, and analyze x-ray spectra. One advantage of a personal computer (PC) based system is the low cost--approximately 20% of the cost of other options. A second advantage is that a system can be developed which is tailored to the needs of the laboratory, so that experimental questions asked of the data can dictate procedures for data acquisition and processing.We have developed a PC-based system for electron probe microanalysis, which we use for data acquisition, processing, and analysis of frozen and freeze-dried biological samples. X-ray spectra may be acquired either for spot analysis or for elemental images. Spectra acquired from large areas of the frozen, hydrated sample are used together with spectra from the freeze-dried specimen to calculate concentrations relative to sample wet weight.

Reduction of Potassium in Kidney Proximal Tubules to Aid in Electron Probe X-Ray Microanalysis of Calcium

1985 ◽  
Vol 43 ◽  
pp. 474-475
Author(s):  
A. LeFurgey ◽  
P. Ingram ◽  
L.J. Mandel
Keyword(s):  
Smooth Muscle ◽  
Proximal Tubule ◽  
Electron Probe ◽  
Clinical Applications ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Target Cells ◽  
X Ray ◽  
Freeze Dried

For quantitative determination of subcellular Ca distribution by electron probe x-ray microanalysis, decreasing (and/or eliminating) the K content of the cell maximizes the ability to accurately separate the overlapping K Kß and Ca Kα peaks in the x-ray spectra. For example, rubidium has been effectively substituted for potassium in smooth muscle cells, thus giving an improvement in calcium measurements. Ouabain, a cardiac glycoside widely used in experimental and clinical applications, inhibits Na-K ATPase at the cell membrane and thus alters the cytoplasmic ion (Na,K) content of target cells. In epithelial cells primarily involved in active transport, such as the proximal tubule of the rabbit kidney, ouabain rapidly (t1/2= 2 mins) causes a decrease2 in intracellular K, but does not change intracellular total or free Ca for up to 30 mins. In the present study we have taken advantage of this effect of ouabain to determine the mitochondrial and cytoplasmic Ca content in freeze-dried cryosections of kidney proximal tubule by electron probe x-ray microanalysis.

Electron microprobe study of turquoise-group solid solutions in the Neyshabour and Meydook mines, northeast and southern Iran

2020 ◽  
Vol 58 (1) ◽  
pp. 71-83
Author(s):  
Elahe Mansouri Gandomani ◽  
Nematollah Rashidnejad-Omran ◽  
Amir Emamjomeh ◽  
Pietro Vignola ◽  
Tahereh Hashemzadeh
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Electron Microprobe ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Major Elements ◽  
Point Of View ◽  
Chemical Compositions ◽  
Light Blue ◽  
Quaternary Solid Solution

ABSTRACT Turquoise, CuAl6(PO4)4(OH)8·4H2O, belongs to the turquoise group, which consists of turquoise, chalcosiderite, aheylite, faustite, planerite, and UM1981-32-PO:FeH. In order to study turquoise-group solid solutions in samples from the Neyshabour and Meydook mines, 17 samples were selected and investigated using electron probe microanalysis. In addition, their major elements were compared in order to evaluate the feasibility of distinguishing the provenance of Persian turquoises. The electron microprobe data show that the studied samples are not constituted of pure turquoise (or any other pure endmember) and belong, from the chemical point of view, to turquoise-group solid solutions. In a turquoise–planerite–chalcosiderite–unknown mineral quaternary solid solution diagram, the chemical compositions of the analyzed samples lie along the turquoise–planerite line with minor involvement of chalcosiderite and the unknown mineral. Among light blue samples with varying hues and saturations from both studied areas, planerite is more abundant among samples from Meydook compared with samples from Neyshabour. Nevertheless, not all the light blue samples are planerite. This study demonstrates that distinguishing the deposit of origin for isochromatic blue and green turquoises, based on electron probe microanalysis method and constitutive major elements, is not possible.

Elemental content of mast cell granules measured by X-ray microanalysis of rat thymic tissue sections

1986 ◽  
Vol 83 (1) ◽  
pp. 77-87 ◽  
Author(s):  
M.D. Kendall ◽  
A. Warley
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Elemental Content ◽  
Thymic Tissue ◽  
X Ray ◽  
Tissue Sections ◽  
Freeze Dried ◽  
The Mean ◽  
Highly Correlated ◽  
The Individual

Mast cell granules were examined by fully quantitative X-ray microanalysis of 20 cells in freeze-dried cryosections. The mast cells were situated mainly in the connective tissue of the thymic capsule of five adult male Carworth Sprague Europe rats. In addition 30 red blood cells were analysed from the same sections. Nineteen of the mast cells had granules rich in S and K. One cell had smaller granules, and in this cell the granules contained high [Ca] and [P] instead of high [S] and [K]. In the majority of cells (13) the S:K ratio was highly correlated and less than 2.2, whereas in the remaining six cells the individual granule ratios were very variable in any one cell and much higher. The mean granule [K] (994 +/− 57 mmol kg-1 dry wt) was about four times the mean cytoplasmic level of 227 +/− 81 mmol kg-1 dry wt. The existence of this difference in concentration between the granules and the cytoplasm suggests that the K in the granules must be bound. The relationship between the [K] and [S] is discussed with regard to the possible binding of heparin and amines in the granules.

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