Life Sciences Commons^™

Quantitative Imaging In Electron And Confocal Microscopies For Applications In Biology, N. Bonnet, L. Lucas, D. Ploton

Scanning Microscopy

Among the large number of topics related to the quantification of images in electron and confocal microscopies for applications in biology, we selected four subjects that we consider to be representative of some recent tendencies. The first is the quantification of three-dimensional data sets recorded routinely in scanning confocal microscopy. The second is the quantification of the textural and fractal appearance of images. The two other topics are related to image series, which are more and more often provided by imaging instruments. The first kind of series concerns electron energy-filtered images. We show that the parametric (modelling) approach can be …

A Reflection Upon The Applicability Of Electron Beam Induced Current (Ebic) As A Sensitive Microanalytical Technique (Ppb Range) For Silicon Materials Research, Martin Kittler, Winfried Seifert

Scanning Microscopy

This paper discusses the application of electron-beam-induced current (EBIC) technique as a tool which is able to provide at least qualitative microanalytical information not available from other techniques. Three examples are given which demonstrate a sensitivity in the parts per billion (ppb) range: temperature dependence of dislocation contrast as a fingerprint of level of metal (Cu) contamination, iron determination down to 1013 atoms per cm3, and visualization of phosphorous striations in silicon grown by float-zone (FZ) method (FZ-grown Si).

Microanalytical information by EBIC is rather indirect and, usually, identification of the impurity species is not possible. Conclusions about impurity content …

New Applications Of The Nuclear Microprobe For Biological Samples, Jan Pallon, Klas Malmqvist

Scanning Microscopy

The continuing development of the Nuclear Microprobe (NMP) has opened up new fields of applications in biology and medicine. Quantitative multielemental analysis in small sections of samples can be performed routinely. The use of techniques such as scanning transmission ion microscopy makes imaging as well as mass normalization possible at submicron resolution. Recent medical applications include studies on thin cryosections prepared from autopsies and biopsies, as well as single cells grown directly on the backing foil used in the NMP analyses. The purpose of the single cell analysis is often pharmacological, e.g., testing of new drugs, their uptake and distribution. …

X-Ray Microanalysis Of Endocrine, Exocrine And Intestinal Cells And Organs In Culture: Technical And Physiological Aspects, Romuald Wróblewski, Joanna Wroblewski

Scanning Microscopy

In the present study methods for preparation of cultured cells and organ cultures for analytical electron microscopy are investigated. These methods allow qualitative and quantitative analysis of mobile ions in combination with biochemical or morphological studies. Cultured cells can be easily prepared for analytical microscopy and therefore use of in vitro systems for X-ray microanalysis has increased over the last few years. Two major, anhydrous preparation techniques, by which loss or redistribution of ions is minimized, were used: (1) Cells were cryosectioned and analysis carried out on freeze-dried sections obtained from frozen cell monolayers, pelleted cells or organ cultures. (2) …

Imaging-Sims (Secondary Ion Mass Spectroscopy) Studies Of Advanced Materials, R. Levi-Setti, J. M. Chabala, J. Li, K. L. Gavrilov, R. Mogilevsky, K. K. Soni

Scanning Microscopy

This article describes the application of scanning ion microprobe (SIM) microanalysis for the characterization of advanced engineered materials. In conjunction with secondary ion mass spectrometry (SIMS), scanning ion microprobes can image elemental distributions over surfaces with high lateral resolution (50-100 nm). With this technique, most elements, including isotopes, can be detected with good sensitivity. The principles and instrumentation associated with the SIM/SIMS technique are briefly described and ongoing developments are outlined. The analytical capabilities of the technique are illustrated by case studies of aluminum-lithium alloys, zinc oxide varistors, aluminum matrix composites, and photographic materials.

Intracellular And Extracellular Elemental Composition Of The Endolymphatic Sac Studied By X-Ray Microanalysis, Romuald Wroblewski

Scanning Microscopy

X-ray microanalysis was performed along with light microscopy (LM) on rapidly frozen and cryo-sectioned endolymphatic sac tissues of adult guinea pigs, to determine the elemental composition of the different cell types in this tissue as well as the content of the sac lumen. The morphological preservation and spatial resolution of cryo-sectioned endolymphatic sac was found adequate for the identification of the different cell types of the sac in the transmission electron microscope. Further cell type identification was performed by comparing scanning transmission electron microscopy images with LM images on adjacent serial sections. X-ray microanalysis demonstrated differences between epithelial and sub-epithelial …

X-Ray Microanalysis Of Chief Cells In Rat Parathyroid Gland, Romuald Wroblewski

Scanning Microscopy

X-ray microanalysis was used to study the elemental composition of the rat parathyroid gland. Analyses were performed in morphologically defined cells. Use of semi-thin cryosections allowed us to selectively analyze cell nucleus, cytoplasm and occasionally dense granules in the cytoplasm.

The concentration of elements (mmol/kg dry weight) in chief cells of parathyroid gland were as follows: Na 83, Mg 48, P 853, S 224, Cl 164, K 551 and Ca 10. Significantly higher phosphorus and potassium concentrations were found in the dense granules as compared to cytoplasm of the parathyroid chief cells. Choosing rat parathyroid gland gave the possibility to …

Keynote Paper: The Scanning Electron Microscope (Sem) Supplemented By The Polarized Light Microscope (Plm), And Vice Versa, Walter C. Mccrone

Scanning Microscopy

The scanning electron microscope (SEM) yields excellent topographic and other shape information and, when fitted with an energy dispersive system (EDS), elemental composition. The polarized light microscope (PLM) on the other hand, delivers information on the internal properties of small particles, fibers, and films. By determining optical properties as well as shape, PLM determines molecular, rather than elemental, composition. Both SEM and PLM have impressive records for problem solving in the research and development world and each is usually applied without aid from the other. Examples are given of important problems that have been solved by supplementary PLM with SEM …

Recent Developments In Multichannel Raman Microprobing, J. Barbillat, M. Delhaye, E. Da Silva

Scanning Microscopy

This paper reviews the capabilities of multichannel Raman microprobing instruments with emphasis on some major innovative progress recently proposed which looks promising for the development of new fields of application. This new progress includes: confocal Raman microanalysis that provides better spatial resolution and background rejection, confocal Raman mapping that revitalizes the field of Raman imaging pioneered by us 20 years ago, the coupling of molecular Raman microanalysis to elemental electron microprobe, and finally, Raman spectroscopy with near-infrared excitation which permits avoiding the fluorescence limitation of visible Raman spectroscopy.

Histochemical Demonstration And Microanalysis Of Possible Calcium Binding Sites In The Enamel Organ Of Rat Incisors, Y. Takano

Scanning Microscopy

The rat incisors obtained from rats perfused with high-calcium solution containing 30 to 50 mM CaCl₂ were processed for rapid freeze/freeze-substitution and embedded in epoxy resin. GBHA staining, a histochemical staining for calcium, of unhydrously prepared sections revealed a large number of granular Ca-GBHA reactions in the enamel organ, most of which being located along the lateral plasma membranes of the ameloblasts. In the ameloblast layer, the reaction was negative in the presecretory stage, became intense in concert with the onset of enamel matrix formation, and remained so by the end of the transitional stage where the reaction gradually …

Multi-Dimensional Data Analysis And Processing In Electron-Induced Microanalysis, N. Bonnet, P. Trebbia

Scanning Microscopy

The new facilities offered by computer controlled data capturing devices allow one to open the field of data acquisition from one or two-dimensional spaces to multi-dimensional ones. The methods used for analysing and processing such data sets have to move in parallel towards multi-dimensionality. Multivariate Statistical Analysis is one of the tools which appear to be promising in : data analysis, data reduction, data processing (multivariate noise filtering), data interpolation and extrapolation. Illustrations of these different possibilities are given in the fields of spatially resolved spectroscopy, time-dependent spectroscopy and elemental mapping from Electron Energy Loss Spectroscopy.

Data Acquisition And Presentation In Scanning Nuclear Microprobe Analysis, K. G. Malmqvist, N. E. G. Lövestam, J. Pallon, U. A. S. Tapper

Scanning Microscopy

The data acquisition is a very important part of the scanning nuclear microprobe instrument. To make full use of the potential of the technique an adequate system for acquiring, storing, processing and presenting the data is a prerequisite. Various principles applied are presented including the list mode approach, which facilitates flexible off-line data processing. As in the case of the electron probe the beam-induced effects in the sample may be substantial and the list mode acquisition can then also be used to monitor and correct for any such effects. A comprehensive system for scanning nuclear microprobe control and data acquisition, …

Proton Microprobe And Particle Induced X-Ray Emission (Pixe) Analysis For Studies Of Pathological Brain Tissue, K. G. Malmqvist, A. Brun, K. Inamura, E. Martins, L. G. Salford, B. K. Siesjö, U. A. S. Tapper, K. Themner

Scanning Microscopy

Particle Indiced X-ray Emission and proton microprobe analyses have been applied for the investigation of regional elemental distributions in connection with various pathological states in the brain. Malignant brain tumours and adjacent histologically intact tissue removed during surgery were analysed with PIXE. Systematic elemental variations, e.g., for calcium and selenium, were observed in the tumour front. The proton microprobe was applied to study the Ca and K concentrations in various cell strata in hippocampus following transient ischaemia in rat brain. Significant increases in the Ca level occurred in selectively vulnerable cells within 48 h after the ischaemia.

Scanning Electron Microscopy And Electron Probe Microanalyses Of The Crystalline Components Of Human And Animal Dental Calculi, R. Z. Legeros, I. Orly, J. P. Legeros, C. Gomez, J. Kazimiroff, T. Tarpley, B. Kerebel

Scanning Microscopy

A review of the use of scanning electron microscopy (SEM) and electron probe microanalyses in the study of dental calculus showed that such studies provided confirmatory and supplementary data on the morphological features of human dental calculi but gave only limited information on the identity of the crystalline or inorganic components.

This study aimed to explore the potential of combined SEM and microanalyses in the identification of the crystalline components of the human and animal dental calculi. Human and animal calculi were analyzed. Identification of the crystalline components were made based on the combined information of the morphology (SEM) and …

Electron Energy Loss Spectroscopic Imaging In Biology, G. T. Simon, Y. M. Heng

Scanning Microscopy

One of the goals in biology is to relate the ultrastructure with the movement of elements to under stand better physiological and pathophysiological mechanisms. Electron energy loss spectroscopy (EELS) imaging, which was developed in the last decade, appears to be an ideal technique to make such correlation.

EELS takes advantage of the energy distribution of transmitted electrons which interacted with the specimen. All these electrons are collected and can be displayed as an energy loss spectrum for analytical purposes. Images can be produced from selected regions from the energy distribution allowing the mapping of specific elements. The main advantage of …

Intrauterine Device (Iud) Associated Pathology: A Review Of Pathogenic Mechanisms, Waldemar A. Schmidt, Karmen L. Schmidt

Scanning Electron Microscopy

This paper summarizes our studies of IUD-related disease with those previously published by others. Our data are based upon 51 IUDs and 42 index cases of IUD-related disease demonstrating specific processes. Gross, dissecting microscope, scanning electron microscope and X-ray microanalysis examinations were made of selected IUDs and associated tissues. Tissue associated with the IUDs revealed inflammation in 59.4%, calcific material in 6.3% and no abnormality in 34.4%. JUD-associated tissue responses were accompanied by changes of the IUD; these changes involved deposition of substances upon the IUD surface and degradation of the JUD itself. Disintegration of the IUD, its string or …

The Cathodoluminescence Mode Of The Scanning Electron Microscope: A Powerful Microcharacterization Technique, D. B. Holt, F. M. Saba

Scanning Electron Microscopy

By detecting cathodoluminescence (CL) in a scanning electron microscope (SEM), pan and monochromatic micrographs and CL spectral analyses analogous to x-ray mode point analyses can be obtained. Complete microcharacterization requires alternate examination of both micrographs and spectra. New techniques for near infra-red CL and low-temperatures to produce sharp spectra are of increasing importance. CL emission is due to electron transitions between quantum mechanical states so the radiative defects present can be unambiguously identified at liquid helium temperatures. Strongly luminescent impurities can be detected to below one part in 10⁸. This is 10⁴ times as sensitive as the …

Secondary Electron Imaging In The Scanning Transmission Electron Microscope, R. M. Allen

Scanning Electron Microscopy

The detailed correlation of surface morphology and subsurface microstructure has been made possible by the scanning transmission electron microscope. This instrument provides the capability for simultaneous and independent secondary electron and transmitted electron imaging from the same sample area. This includes the ability to generate mixed secondary/transmitted electron images, which form a concise visual presentation of the information in the two component images.

Correlative surface and through-volume specimen examination of this type has most frequently been applied to backthinned samples, which are specifically prepared in a way which produces electron-transparent material in the immediate vicinity of a surface of interest …

Progress In Element Analysis On A High-Voltage Electron Microscope, W. F. Tivol, D. Barnard, T. Guha

Scanning Electron Microscopy

X-Ray microprobe (XMA) and electron energy-loss (EELS) spectrometers have been installed on the high-voltage electron microscope (HVEM). The probe size has been measured and background reduction is in progress for XMA and EELS as are improvements in electron optics for EELS and sensitivity measurements.

XMA is currently useful for qualitative analysis and has been used by several investigators from our laboratory and outside laboratories. However, EELS background levels are still too high for meaningful results to be obtained. Standards suitable for biological specimens are being measured, and a library for quantitative analysis is being compiled.

Energy Selecting Electron Microscopy, F. P. Ottensmeyer

Scanning Electron Microscopy

One of the major improvements in transmission electron microscopy over the last years is the addition of the capability of producing images with electrons that have specific narrow energy bands out of the total spectrum of energies they possess after having passed through the specimen. Though the idea is not new, the power of this application is only beginning to be recognized. Most simply, selection of elastically scattered electrons permits increased contrast in high resolution i mages in bright field, dark field, and diffraction. The use of combined elastic and inelastic signals adds entirely new contrast mechanisms, partially independent of …

Electron Energy Loss Microspectroscopy And The Characterization Of Solids, Richard Leapman

Scanning Electron Microscopy

The inelastic scattering of fast electrons provides a detailed means of characterizing the chemical composition and electronic properties of thin samples in an electron microscope. Collective and single-electron excitations occuring in the low energy region of the spectrum can be described in terms of the generalized dielectric formulation. Important information is contained in this part of the spectrum but some prior detailed knowledge of the sample is usually required for proper interpretation. The core excitations allow microanalytical information to be obtained and quantitative procedures are now quite well developed at least for K and L edges. Sample thickness is one …